Intro to Statistics Unit 1
Julie wanted to find out the approximate percentage of non-traditional female college students at public universities. She decided to randomly select 25 females from each university in her state and collect and analyze the data. The sample is (A) __________. The population is (B) __________.
(A) 25 (B) All female college students at state universities
A company packed 8 dark chocolates in a box of 32 assorted chocolates.Which of these does not represent inferential statistics? 25% of the chocolates manufactured in a factory are dark chocolates. 25% of the chocolates packed in a day are dark chocolates. 25% of the chocolates manufactured in a batch are dark chocolates. 25% of the chocolates in the box are dark chocolates.
25% of the chocolates in the box are dark chocolates.
Which of these random samples qualifies as a representative sample if studying the opinion of the attendees to a business seminar? 35 people whose businesses are related to the topics discussed at the seminar 35 people who spoke at the seminar 35 people who attended the seminar 35 people of the company that organized the seminar
35 people who attended the seminar
A bakery owner asked 150 customers to taste a new type of cookie and found that 60 people liked its taste.Which of these is an example of descriptive statistics? 40% of all the bakery's customers like the taste of the cookie. 40% of the surveyed customers like the taste of the cookie. 40% of all people like the taste of the cookie. 40% of the people in the city where the bakery is located like the taste of the cookie.
40% of the surveyed customers like the taste of the cookie.
Which of these random samples qualifies as a representative sample to find out what parents think about the levels of college tuition fees in the state? 50 residents of a city in the state 50 residents of a county in the state 50 parents of college students from the state 50 parents of school students from another state
50 parents of college students from the state
A survey on internet usage was conducted among a group of 200 students in the cafeteria at a school. It was found that 100 students spend at least 2 hours online every day.Which of these is an example of descriptive statistics? 50% of the students in a class spend at least 2 hours online each day. 50% of the students in the cafeteria spend at least 2 hours online each day. 50% of the students in the school spend at least 2 hours online each day. 50% of the students surveyed spend at least 2 hours online each day.
50% of the students surveyed spend at least 2 hours online each day.
Statistical analysis of the surveys showed that for the question about "handset selection", the mean score was 7.2, with a margin of error of 0.9. In order from lowest to highest, the interval estimate ranges from (A) _____________ to (B) _____________ .
6.3 - 8.1
Match each study with its corresponding definition. A - Observational study B - Experiment C - Survey Measuring variables of interest but not attempting to influence responses
A - Observational study
How is the Nielsen rating measured?A. Viewer diariesB. Set metersC. Random SamplingD. Telephone surveys B and D A and B B and C A and D
A and B
Survey/Sample Survey
A data collection tool that individuals in a study can fill out and return to the researcher.
Which of these statements best describes a matched-pair design? A design in which the total population is randomly divided into groups of equal size and a treatment is assigned to each group. A design in which the total population is divided into homogeneous blocks and a treatment is assigned to every element of the block. A design in which the sample is divided roughly into some groups and then some of the groups are randomly selected. A design in which the matched elements are grouped in pairs and then, within each pair, subjects are randomly assigned to different treatments.
A design in which the matched elements are grouped in pairs and then, within each pair, subjects are randomly assigned to different treatments.
Treatment Group
A group that is manipulated by the treatments in the experiment. There may be many treatment groups in an experiment, but only one control group.
Control Group
A group which receives no treatment (or an inert treatment) in an experiment. This group's response provides a standard against which the response to the treatment(s) can be compared.
Nielsen Radio Index
A method for measuring radio listenership that was first used in 1942.
Random Number Generator
A method of collecting a sample that utilizes technology to select random numbers corresponding to individuals in the population
Random Number Table
A method of collecting a sample to select random numbers corresponding to individuals in the population. Each individual is assigned a number, which are then selected from the table.
Simple Random Sample
A method of selection that guarantees that every sample of a certain size has an equal chance of being the selected sample
Subject/Participant
A person involved in an experiment.
Nielsen Ratings
A public interest study that measures mainly retail and media consumption.
Stratified Random Sample
A random sampling method where individuals are separated into homogenous groups, then simple random samples are taken within each group.
Confidence Interval
A range of potential values that the true value could be. It is obtained by adding and subtracting the margin of error from sample mean.
Which of the following statements is true about observational studies? A researcher can carefully control the explanatory variables but not observe them. A researcher can carefully control the response variables but not observe them. A researcher can observe the explanatory variables but not control them. A researcher can minimize the explanatory variables but not eliminate them. A researcher can completely eliminate the effects of any explanatory variables.
A researcher can observe the explanatory variables but not control them.
Random Sample
A sample that has been selected in a manner where every member of the population has some predetermined chance of being selected for the sample
Multi-Stage Sampling
A sampling design which combines elements of cluster sampling, stratified random sampling, and simple random sampling. It "zooms in" on smaller areas to sample so that sampling becomes more feasible.
Systematic Random Sample
A sampling method where every "k"th individual is selected for the sample (e.g. every 2nd, 4th, 20th individual)
Cluster Sample
A sampling method where the population is separated into groups, typically geographically, and a random selection of clusters is made. Each individual in the cluster becomes part of the sample.
Pilot Survey
A smaller scale version of a survey to determine if there is reason to do a larger version of the survey.
Pilot Experiment
A smaller scale version of an experiment to determine if there is reason to do a larger version of the experiment.
Pilot Study
A smaller scale version of an experiment, survey, or observational study to determine if there is reason to do a larger version of the study.
Prospective Study
A study that begins by selecting participants, then tracks them and keeps data on the subjects as they go into the future.
Retrospective Study
A study that observes what happened to the subjects in the past, in an effort to understand how they became the way they are in the present.
Observational Study
A type of study where researchers can observe the participants, but not affect the behavior or outcomes in any way.
Experiment
A type of study where researchers impose treatments on the participants or experimental units.
Response Variable
A variable that is affected by the explanatory variable.
Explanatory Variable
A variable that we believe is predictive of something else. An increase in this variable will correspond to an increase or decrease in some other variable.
Confounding Variable
A variable which was not accounted for in a study, which limits the conclusions that the study can draw.
Statistical study
A way to collect information from individuals
Match each type of sampling with its corresponding instruction. A. Simple Random Sampling B. Systematic Sampling C. Convenience Sampling D. Cluster Sampling E. Stratified Sampling _____Choose a sample so that every member of the population has an equal chance of being selected for the sample.
A. Simple Random Sampling
Statistical analysis
All the ways of collecting, analyzing, and interpreting the data
Margin of Error
An amount by which we believe our sample's mean may deviate from the true mean of the population.
Experimental Unit
An animal or thing involved in an experiment.
Clinical Trial
An experiment where a pharmaceutical company or government agency tests the safety and efficacy of an experimental drug, medical device or therapy for human use.
Single-Blind Experiment
An experiment where either the subjects have no knowledge of which subjects are receiving which treatment, or people in contact with the subjects have no knowledge of which subjects are receiving which treatment, but not both.
Double-Blind Experiment
An experiment where neither the subjects, nor anyone in contact with them, has any knowledge of which subjects are receiving which treatment.
Completely Randomized Design
An experimental design where the assignment of subjects to treatments is done entirely at random.
Randomized Block Design
An experimental design where the subjects are separated into homogeneous groups, called blocks, based on some variable we think may affect the outcome of the experiment. We then run the experiment separately within each block.
Matched-Pair Design
An experimental design where two subjects who are similar with respect to variables that could affect the outcome of the experiment are paired together, then one of them is assigned to one treatment and one is assigned to the other. This can also be done by assigning each subject to both treatments, where each subject acts as their own matched-pair.
Placebo
An inert drug or treatment given to the control group. It has no active ingredient in it.
Variable
Any attribute or number that can be measured about individuals in a study.
Variable of Interest
Any variable which we need to know about in the context of a study.
Which of these is an example of a blind experiment? Asking a group of students to compare the tastes of different brands of potato chips without revealing the names of the brands. Asking a group of kids to choose their favorite candy from a jar containing different candies. Asking a group of students about their favorite sports from a list containing names of ten sports. Asking a group of students about the candidate they will vote for in the school elections.
Asking a group of students to compare the tastes of different brands of potato chips without revealing the names of the brands.
Tim works in the public relations department of a cell phone company and is interested in getting information on how satisfied customers are with their cell phone service. He knows he is going to end up creating his own survey, but for now he wants to see what else is out there. Tim finds some public records about customer satisfaction. This kind of data is called __________ data.
Available
Match each study with its corresponding definition. A - Observational study B - Experiment C - Survey Doing something intentionally to the individuals involved
B - Experiment
Betty wants to determine if drinking at least five carbonated sodas a week improves a student's grade point average (GPA). From a random group of students, some will drink more than five sodas a week and the rest will drink less. After a number of years, the GPAs are compared. Which of the following types of statistical study is this? A. Census B. Experiment C. Observational study D. Questionnaire E. Survey
B. Experiment
Researchers in Fargo, North Dakota, randomly divided 1,000 marathon runners into three groups. One group received a daily muscle relaxant pill, one group received a fish oil pill, and the third group received a sugar pill. Supplements were given for one month. Five years later, the marathon runners returned and had an MRI done on their muscles. It was found that there was less scar tissue in the runners who used the daily muscle relaxant pill than in those who were given the fish oil pill or sugar pill. This study is an example of which of the following? A. Census B. Experiment C. Observational study D. Survey E. None of the above
B. Experiment
Match each type of sampling with its corresponding instruction. A. Simple Random Sampling B. Systematic Sampling C. Convenience Sampling D. Cluster Sampling E. Stratified Sampling _____ Choose a sample in such a way that every nth person or item is included.
B. Systematic Sampling
A researcher obtains a sample of participants for a taste-test survey. However, after analyzing the sample carefully, the researcher finds that the general make-up of the sample differs significantly from the population of interest. The researcher concludes that it is possible that __________ may have influenced the results of the sample.
Bias
One typical way to select a sample is to randomly pick phone numbers from a telephone book. This method can introduce __________, because those that cannot afford a telephone, chose not to have a telephone, or do not list their phone numbers will not be represented.
Bias
Response Bias
Bias that occurs when a respondent tells the interviewer "what they want to hear" or lies due to the sensitive nature of the question.
Participation (Voluntary Response) Bias
Bias that occurs when a sample consists entirely of volunteers. People with strong opinions may be the only ones who volunteer.
Match each study with its corresponding definition. A - Observational study B - Experiment C - Survey Selecting a sample from the population of all individuals about which information is desired
C - Survey
Match each type of sampling with its corresponding instruction. A. Simple Random Sampling B. Systematic Sampling C. Convenience Sampling D. Cluster Sampling E. Stratified Sampling _____ Use a sample that happens to be hassle-free to select and is typically not representative of the population.
C. Convenience Sampling
Which of these is true about a blinding experiment? Elements are equally divided into groups. All information is shared with the participants. Certain information is hidden from the participants. Closely matched elements are paired and then treatments are allotted to them.
Certain information is hidden from the participants.
A group of 100 people were given different doses of aspirin and its effect on their sleeping patterns were observed. What can this be classified as? Placebo Blinding Clinical trial Meta-analysis
Clinical trial
A group of 100 women were put on different combinations of fruit diets for two weeks and their weight loss was monitored. What can this be classified as? Placebo Blinding Meta-analysis Clinical trial
Clinical trial
A pharmaceutical company is working on a new drug, which helps improve eyesight. It gives different dosages of the drug to a group of 50 people and observes changes in their eyesight's over the next few months. What can this be classified as? Placebo Blinding Clinical trial Meta-analysis
Clinical trial
The type of experimental design where the assignment of experimental units to treatment and control groups is random is called a(n) __________.
Completely Randomized Design
Jenny conducted a survey to study the relationship between income and cell phone use. After examining the results closely, she suspects that the age of the respondent might be influencing both income and cell phone use. In Jenny's survey, age would be considered a(n) __________ variable.
Confounding
Confounding
Confounding occurs when the effects, if any, of the treatments are indistinguishable from the potential effects of some other variable which was unaccounted for.
A recent research study suggests that decrease in the daily temperature causes an increase in the number of people heading to the beach.Which of these can be responsible for the results of the research being incorrect? Ordinal variable Confounding variable Response variable Dependent variable
Confounding variable
A recent research study suggests that eating chocolates results in losing weight.Which of these can be responsible for the results of the research being incorrect? Ordinal variable Response variable Confounding variable Dependent variable
Confounding variable
A recent research study suggests that excessive drinking leads to decelerated aging.Which of these can be responsible for the results of the research being incorrect? Dependent variable Independent variable Nominal variable Confounding variable
Confounding variable
Jenae noticed that many of her coworkers would opt for the coffee that appeared to be most recently brewed, regardless of the flavor of the coffee offered. This leads her to believe that what she was witnessing was not really representative of everyone's true flavor preferences. As a consequence, Jenae decided make sure that pots with the different coffee flavors were always brewed at the same time. By keeping the freshness of the coffee the same, Jenae is using this variable as the _________ in the experimental study. :
Control
A sample composed of people who are readily available, easily recruited, or volunteer is called a __________ sample.
Convenience
Match each type of sampling with its corresponding instruction. A. Simple Random Sampling B. Systematic Sampling C. Convenience Sampling D. Cluster Sampling E. Stratified Sampling _____ Divide the population into groups, and then randomly select some groups. Choose all the members within the selected groups to be part of the sample.
D. Cluster Sampling
The owner of an ice cream shop would like to determine statistically which age groups (<13, 13-21, 22-35, 36-50, and >50) in his city prefer which flavors of ice cream, in order to figure out how to stock the freezer cases at her store. Which of the following would be the most appropriate study to obtain this information? A. Census B. Experiment C. Observational study D. Survey E. None of the above
D. Survey
Available Data
Data collected by some other entity - a government organization or private company
Which of these situations best describes randomization? Drawing a black card from a well-shuffled standard deck of 52 cards. Number of coins used in an experiment involving coin tosses. Repetition of the same treatment to the patient. Effect of sunlight on plant growth.
Drawing a black card from a well-shuffled standard deck of 52 cards.
A teacher decides to use rewards to help decrease behavioral outbursts in her tutoring service for children with Asperger's syndrome. At the end of one month, several children tell her that the rewards have helped them stay calm. This is an example of which of the following types of studies? A. Survey B. Experiment C. Observational study D. Census E. None of the above
E. None of the above
Match each type of sampling with its corresponding instruction. A. Simple Random Sampling B. Systematic Sampling C. Convenience Sampling D. Cluster Sampling E. Stratified Sampling _____ First divide the population into groups, and then randomly pick Individuals from each group, so that the sample is proportionate to the population.
E. Stratified Sampling
Which of these statements is true for simple random sampling? A simple random sample is an unequal probability sampling method. Each element of the sample is chosen in a deterministic manner. A simple random sample is a biased surveying technique. Each element of the sample has the same probability of being chosen.
Each element of the sample has the same probability of being chosen.
In which of these is a Gallup poll most widely used? Surveys on environment issues Medical care surveys Magazine surveys Election surveys
Election surveys
Which of these statements is true for stratified random sampling? The probability of any element being selected from the total population is always the same. Elements are randomly selected from groups in proportion. Every nth element is selected from the total population. Each element is chosen randomly from the total population.
Elements are randomly selected from groups in proportion.
Which of these statements is NOT true regarding a randomized block design experiment? This design has an advantage of controlling for variables that might confound the response. Elements are randomly selected from the divided blocks of the total population. The elements are randomly allocated to treatment and control groups The sample is divided into participants or subjects into groups by a variable of interest
Elements are randomly selected from the divided blocks of the total population.
Which of these statements is NOT true for stratified random sampling? Elements are randomly selected from the total population. The total population is divided into groups, and then elements are randomly selected in proportions. The probability of different elements of the sample being chosen is unequal. Groups are selected so that they are homogeneous with respect to some important characteristic.
Elements are randomly selected from the total population.
Which of these statements is NOT true regarding cluster sampling? Every element of some groups are included in the sample. Some of the groups are randomly selected. Every element of the total population has an equal probability of being selected. The total population is divided into groups.
Every element of the total population has an equal probability of being selected.
A gas company wants to compare the effectiveness of a newly formulated, premium fuel to its regular-grade fuel. The company obtains a sample of race-car drivers and then divides the drivers into two groups. One group uses the premium fuel, and the other uses the regular-grade fuel. The company tests the performance of the fuels and compares the increase in take-off speed between the two groups. The kind of statistical study this scenario describes is a(n) __________.
Experiment
Subjects and participants are types of which of these? Experiments Experimental units Control groups Treatments groups
Experimental units
Select the statement that expresses an advantage that is unique to experiments, and is NOT possible with either surveys or observational studies. Experimenters can work with a sample that represents the population as a whole. Experimenters can gather data that provides a deeper understanding of the situation. Experimenters can use sample data to draw inferences about the population. Experimenters can observe and record information of interest. Experimenters can use the data to draw cause and effect relationships. Experimenters can reach a wider range of individuals.
Experimenters can use the data to draw cause and effect relationships.
"Effect of temperature on the rate of reaction of an experiment"What type of variable is "temperature" in the experiment? Categorical Qualitative Response Explanatory
Explanatory
In experiments, a(n) __________ variable is controlled to explain a cause and effect relationship.
Explanatory or Independent
Evaluate whether the statements about sampling is "True" or "False." Convenience sampling is recommended because it is easy and highly reliable.
False
Evaluate whether the statements about sampling is "True" or "False." Taking a census is the most practical approach to sampling.
False
Which of these variables is a continuous variable? Number of houses in a local community Number of members on a soccer team Height of a person Number of cars in a parking lot
Height of a person
A survey needs to be conducted to know the average number of savings accounts held by residents of a community. Which question needs to be used in the survey? Do you deposit money in your bank regularly? How many savings accounts do you have? How many banks do you regularly use? In which bank do you have a savings account?
How many savings accounts do you have?
Which of these statements best explains cluster sampling? In the cluster sampling method, total population is roughly divided into groups and a simple random sample of the groups is taken. The cluster sampling method is a combination of random sampling techniques. In the cluster sampling method, population is broken into groups and then elements are randomly selected in proportion, from each group. In the cluster sampling method, elements are randomly selected from the total population.
In the cluster sampling method, total population is roughly divided into groups and a simple random sample of the groups is taken.
Which of these statements best describes a randomized block design experiment? In this experiment, the subjects are divided into homogeneous blocks and a treatment is assigned to every element of the block. In this experiment, closely matched elements are paired, and then one of them is put in the treatment group and the other in the control group. In this experiment, the subjects are divided into groups by a variable of interest and the elements are then randomly allocated to treatment and control groups within these groups. In this experiment, a sample is divided roughly into some groups and then some of the groups are randomly selected.
In this experiment, the subjects are divided into groups by a variable of interest and the elements are then randomly allocated to treatment and control groups within these groups.
Data
Information used in a study to answer a statistical question.
Which of these is NOT true for meta-analysis? It helps reduce variances in very large sample studies. It finds sources of agreement among results. It discovers relationships that might exist between the results of studies. It identifies patterns among studies.
It helps reduce variances in very large sample studies.
Which of these is true for meta-analysis? It involves only one study. It involves various studies, where the observations of all studies are analyzed together. It involves various studies, where one of the studies is randomly chosen and analysed. It involves various studies, where some of the studies are randomly chosen and analysed.
It involves various studies, where the observations of all studies are analyzed together.
Which of these statements best defines a stratified random sample? It is a sample where every nth element of the population is selected in a sequence. It is a sample where the population is divided into roughly equal groups, and then elements are randomly selected from each group. It is a sample in which every element has the same chance of being selected from the total population. It is a sample where the population is first broken into groups and then elements are randomly selected, in proportion, from each group.
It is a sample where the population is first broken into groups and then elements are randomly selected, in proportion, from each group.
Which of these is true for selection bias in an experiment? It is an effect caused by improper procedures which leads to an unrepresentative sample of participants in a study. It is an effect caused by the tendency of researchers to publish only positive results. It is an effect caused by error in the measurement or classification of participants in a study. It is an effect caused by the tendency of participants in a study to behave differently just because they know they are in a study.
It is an effect caused by improper procedures which leads to an unrepresentative sample of participants in a study.
Which of these statements is true regarding selection bias? It is caused by people in the sample not being available at the time of the survey. It is caused by an incorrect survey question being included in the survey. It is caused by an incorrect sample being chosen. It is caused by people in the sample not answering the questions in the survey.
It is caused by an incorrect sample being chosen.
Which of these statements is true regarding selection bias? It is caused by confounding variables. It is caused by inaccurate questions asked in the survey. It is caused by error in choosing the individuals to take part in a study. It is caused by error in choosing the individuals who will conduct the survey.
It is caused by error in choosing the individuals to take part in a study.
Which of these statements is NOT true for a pilot study for an experiment? It can reveal deficiencies in the design of a proposed experiment or procedure. It is generally carried out after a survey to know the time duration and expenses incurred for the survey. It is frequently carried out before large-scale quantitative research. It evaluates factors such as time, cost, feasibility and others prior to conducting a survey.
It is generally carried out after a survey to know the time duration and expenses incurred for the survey.
Which of these is true for the control group in an experiment? It is not exposed to the factor under consideration and all other external influences are held constant. It is exposed to the factor under consideration and all other external influences are held constant. It is exposed to the factor under consideration and all other external influences are varied. It is not exposed to the factor under consideration and all other external influences are varied.
It is not exposed to the factor under consideration and all other external influences are held constant.
Which of these statements is true regarding a pilot study for an experiment? It is research done after conducting a survey to test the effectiveness of the research methodology. It is research done before conducting a survey to test the effectiveness of the research methodology. It is research done parallel to the survey to test the time taken by the survey. It is research done after conducting a survey to estimate the total expenses incurred in the survey.
It is research done before conducting a survey to test the effectiveness of the research methodology.
Which of these is true for a Gallup poll? It is used to predict the number of voters who voted for the elected president It is used in predicting the result of presidential elections. It is used to predict the number of voters who voted against the elected president It is used to predict the number of voters in the presidential elections
It is used in predicting the result of presidential elections.
Which of these statements is true regarding margin of error in a survey? It is used to find the inaccuracy that is caused by only a portion of population. It is used to express the error caused in a survey result due to incorrect measurement values. It is used to find the deviation of the observation from the expected value. It is used to express the amount of sampling error in a survey's result.
It is used to express the amount of sampling error in a survey's result.
Which of these is an example of multi-stage sampling? Dividing the total population into groups and then selecting individuals in proportion from these groups. Dividing the total population into groups and then making simple random sample of those groups. Making a sample by randomly picking out the addresses in a state. Making a sample at state level, then making a sample of zip codes and then sampling street addresses.
Making a sample at state level, then making a sample of zip codes and then sampling street addresses.
Which of these is an example of multi-stage sampling? Making a sample at state level, then making a sample of zip codes and then sampling the names of people living in that area. Dividing the population into groups and then making simple random samples of those groups. Making a sample by randomly picking out elements from the population. Dividing the total population into groups and then selecting people in proportion from these groups.
Making a sample at state level, then making a sample of zip codes and then sampling the names of people living in that area.
Which of these statements is NOT true regarding the margin of error in a survey? Margin of error is a measure of the precision of a sample estimate of the population value. Margin of error is the estimated range being calculated for a given sample of data. Margin of error is a summary of sampling errors that quantifies uncertainty about a survey result. Margin of error is a way of expressing the amount of sampling error in a survey's result.
Margin of error is the estimated range being calculated for a given sample of data.
Which of these statements is true? Margin of error is used to represent the sampling error in a survey result. Margin of error is used to find the estimated range calculated from a given sample of data. Margin of error is used to find the deviation between the observation and expected value. Margin of error is used to find the human error while calculating the survey result.
Margin of error is used to represent the sampling error in a survey result.
The type of experimental design that groups experimental units based on similar characteristics is called a(n) __________.
Matched-Pair Design
In doing her research, Jenae found that flavor and scent affect how much coffee is consumed. She found many such studies throughout the years on this and found that it satisfied what she found in her own studies with her co-workers. This type of research and study is called __________.:
Meta-Analysis
A nationwide study of hospital service in maternity wards randomly selected 45 hospitals. Every birth mother who had a child during the first week of June at any of these 45 hospitals completed a survey on service received in the maternity ward. This is an example of __________ sampling.
Multi-Stage Cluster
It is important to select a sample in a way that does not introduce bias. Select three examples of "self-selected" sampling. Naomi goes door to door asking questions in a neighborhood that might be a good fit for the restaurant. Naomi posts a request for survey volunteers on the food truck's Facebook page. George offers a free cookie to anyone who agrees to answer their survey questions. George asks the same survey question to everyone who comes to their food truck. Naomi asks a few questions whenever she thinks a customer seems friendly. George mails survey questions to all of the customers who signed up to receive offers and updates from the food truck.
Naomi posts a request for survey volunteers on the food truck's Facebook page. George offers a free cookie to anyone who agrees to answer their survey questions. George mails survey questions to all of the customers who signed up to receive offers and updates from the food truck.
Sample surveys are one form of a(n) __________ statistical study?
Observational
Jenae orders the supplies for her office, including the coffee. She decided to perform a statistical study and see what her co-workers' coffee flavor preferences are. Jenae planned to base her future coffee orders on the data from her study. Jenae decided to have an intern work in the break room and record which flavor of coffee people select and what they add to it for two weeks. Jenae was performing a kind of statistical study called a(n) :
Observational Study
After revising his survey, Tim has decided to conduct the survey using 2500 of his company's current customers. The survey is conducted online, so customers can take it at their convenience. After one week, Tim notices that only 923 people have done the survey, so he sends out another e-mail to those who have not yet completed the survey to remind them to complete the survey. The type of bias that Tim is hoping to minimize is __________.
Participation Bias
Which of these is considered a participant in an experiment? Animals Any noun People Any living thing
People
Hawthorne Effect
People have the tendency to change their behavior when they know they are being monitored.
Which of these is an example of systematic random sample? Picking out 10 names randomly from a group of 50 students. Picking out the telephone number of every 20th person from a directory. Choosing 10 marbles from a jar containing 40 marbles. Selection of one card from a deck of 52 well-shuffled cards.
Picking out the telephone number of every 20th person from a directory.
Tim first decides to try out the first draft of his survey on a small group of 100 people selected using a random sampling technique. What type of survey has Tim performed?
Pilot Study
A child is hurt while playing. His mother applies oil to the wound to pacify the child until they visit the doctor, even though the oil does not have any healing effect. Which of these explains the application of oil to the wound? Meta-analysis Clinical trials Blinding Placebo
Placebo
A person was given water instead of cough syrup without being told. He was later asked if he feels better. Which of these explains this experiment? Clinical trials Blinding Placebo Meta-analysis
Placebo
A vitamin tablet is given to a person suffering from a cold to observe whether the person feels better, even though a vitamin tablet does not cure the common cold. Which of these explains this experiment? Placebo Blinding Meta-analysis Clinical trials
Placebo
Max conducted a clinical trial for a new vitamin supplement. He had two groups in his clinical trial. The control group was given a sugar pill, and the treatment group was given the new vitamin supplement. However, many of the participants in the control group reported improvements in their general health, similar to the treatment group. The __________ effect may describe the reason some participants from the control group reported health improvements.
Placebo
Gallup Poll
Polling method developed by George Gallup whereby a very representative sample can be taken with a fairly small sample size.
Determine whether this example represents a "Sample" or the "Population.": All of the people who could be customers for George and Naomi's restaurant.
Population
In a study to assess the risk of lung cancer with the number of cigarettes smoked per week, researchers randomly selected subjects who smoked, collected data on the number of cigarettes they smoked per week, and made note of which subjects developed lung cancer. This is a(n) __________ statistical study.
Prospective Observational
Following people who are given a new type of medication and noting the side effects refers to which type of statistical study? Survey Prospective observational study Census Retrospective observational study
Prospective observational study
A meta-analysis is likely to suffer from which of these? Response bias Non-response bias Publication bias Selection bias
Publication bias
Which of these is NOT an example of systematic random sample? Picking out every 1000th user who is a member of a social networking site. Random selection of 7 balls from a bag containing 20 balls. Selection of every 10th name from a telephone directory. Selecting every 20th person in a line of 200 moviegoers.
Random selection of 7 balls from a bag containing 20 balls.
Using a fair coin for an experiment involving coin tosses refers to which of these? Control Randomization Replication Blinding
Randomization
They type of experimental design that first divides participants into homogeneous groups before randomly assigning treatments and controls is called a(n) __________.
Randomized Block Design
Which of these examples best represents a simple random sample? Picking out names of every 10th person who drives a car from a group of people. Selecting every 15th person in a group of 100 volunteers. Randomly picking out 20 names from a group of 100 students. Selecting all the students in a group of 50 students.
Randomly picking out 20 names from a group of 100 students.
Replication
Repeating the experiment on multiple subjects/experimental units. This principle of experimental design that states that a larger experiment with more subjects/experimental units will allow us to more clearly see differences between the treatments.
When the temperature difference between the junctions increases, the voltage also increases.What type of variable defines 'voltage"? Qualitative Explanatory Categorical Response
Response
In an experiment, __________ variables are observed when a controlled variable is changed.
Response or Dependent
Determine whether this example represents a "Sample" or the "Population.": All of the individuals who came to the food truck on Wednesday between 11:00 am and 2:00 pm.
Sample
Determine whether this example represents a "Sample" or the "Population.": George and Naomi's most loyal customers, who come to the food truck at least twice a week.
Sample
Selection Bias
Selecting a sample in such a way that certain subsets of the population are systematically excluded.
Which of these is an example of systematic random sample? Selecting every 20th person in a line of 200 moviegoers. Selecting all the students in a class of 30. Picking out 10 names randomly from a bag containing names of 50 students. Randomly selecting 4 balls from a bag containing 20 balls.
Selecting every 20th person in a line of 200 moviegoers.
Based on the small sample using the first draft of his survey, Tim thinks there is enough evidence to show that his sampling method chooses more men than women and he would prefer to have roughly a 50/50 proportion in his sample. What type of bias is this an example of?
Selection bias
Which of these is generally done in a multi-stage sample? A sample is made by randomly picking every nth element of the total population. Simple random samples are made at different stages from the total population. The total population is divided into groups and then some groups are randomly selected. A sample is made by randomly picking out elements from the total population.
Simple random samples are made at different stages from the total population.
Which of these statements is NOT true for simple random sampling? A simple random sample is an equal probability sampling method. Each element of the sample is chosen in a random manner. Simple random sampling involves a biased method of creating a sample. The probability of selecting any element from the total population is the same.
Simple random sampling involves a biased method of creating a sample.
Clusters
Smaller subgroups of the population, not necessarily similar in any way besides all being together in one place, making the individuals easier to sample together.
Which of these statements is true about a blind experiment? The total population is divided roughly into some groups and then some of the groups are randomly selected. Some people involved are prevented from knowing certain information that might lead to biased results. The total population is divided into homogeneous blocks. Closely matched elements are paired and then treatments are allotted to them.
Some people involved are prevented from knowing certain information that might lead to biased results.
Treatment
Something the researchers administer to the subjects or experimental units.
Naomi's suggestion to survey 15 downtown customers and 35 commuters is an example of
Stratified random sample
Which of these statements is true regarding a randomized block design experiment? Matched elements of the total population are divided into pairs. Every element of the total population has the same probability of being chosen. Subjects are broken into groups by a variable of interest and then randomly allocated to the treatment and control groups within these groups. The total population is divided into homogeneous groups or blocks.
Subjects are broken into groups by a variable of interest and then randomly allocated to the treatment and control groups within these groups.
Janae got her results back but did not receive as many as she had hoped for. Janae thinks that the time of year might have influenced the results because it's summer and many people have been taking time off. Janea still wants to compare her findings to those that she found earlier. It seems like her survey supported the idea that people drink more coffee on Mondays than Fridays. Categorize the following variables as response, explanatory, or confounding. Summer : Day of the week : Amount of coffee consumed :
Summer : confounding Day of the week : explanatory Amount of coffee consumed : response
A human resource manager at a large company asked 50 employees in each department to rate the company on employee satisfaction. What type of statistical study is this? Experiment Observational study Survey Census
Survey
A school is planning a field trip for all the students of the school. Ten students are randomly selected from each class of the school and are asked where do they want to go for the field trip. Which type of statistical study is this? Survey Census Experiment Observational study
Survey
The owner of a pizza parlor called every 5th person who ordered pizza last week to rate the pizza. What type of statistical study is this? Survey Census Experiment Observational study
Survey
Naomi's suggestion to survey every 10th person is an example of
Systematic random sampling
Publication Bias
The desire of researchers (and research publications) to only print the most sensational or interesting articles.
Which of these is true for a completely randomized design? The experimental units are assigned randomly to exactly one or more control groups and one treatment group. The experimental units are assigned randomly to exactly one control group and one or more treatment groups. The experimental units are assigned randomly to one or more control groups and one or more treatment groups. The experimental units are assigned randomly to exactly one control group and one treatment group.
The experimental units are assigned randomly to exactly one control group and one or more treatment groups.
Which of these is NOT true for a completely random design? The extraneous variables affect different control groups differently. The design allows flexibility. It minimizes the effects of confounding variables. Any number of treatments may be addressed.
The extraneous variables affect different control groups differently.
Stratum/Strata
The homogenous groups in a stratified random sample. All individuals in each stratum have something in common, and we would like to see how that affects the outcome of the sample.
Which of these is true regarding a matched-pair design? The sample is divided roughly into some groups Each element of the sample is selected at random The matched elements are grouped in pairs The total population is divided into homogeneous blocks
The matched elements are grouped in pairs
Which of these statements is true for a matched-pair design? The matched elements within each pair are randomly assigned to the same treatment. The matched elements within each pair are randomly assigned to different treatments. The matched elements within different pairs are randomly assigned to different treatments. The matched elements within different pairs are randomly assigned to the same treatment.
The matched elements within each pair are randomly assigned to different treatments.
Estimate
The mean value obtained from the sample. If the sample was well-collected, the estimate should be reasonably close to the true value.
Random Selection
The method of obtaining a random sample
Placebo Effect
The observed phenomenon whereby certain individuals will exhibit a desired response even when taking a placebo, which contains no active ingredient.
Subjects/Participants
The people or things being examined in an observational study.
Which of these statements is true regarding a cluster sample? Every kth element of the total population is selected in a continuous manner. The population is divided roughly into groups, some of the groups are randomly selected and then each element in the selected groups are taken as the sample. Selection of elements from the total population to make a sample is made on a random basis. The population is first broken into groups and then elements are randomly selected, in proportion, from each group.
The population is divided roughly into groups, some of the groups are randomly selected and then each element in the selected groups are taken as the sample.
Meta-Analysis
The practice of gathering data from several similar studies to look for overall trends in the data that the studies may have overlooked individually.
Blinding
The practice of making sure that certain individuals do not know which subjects are receiving which treatment.
Control
The principle of experimental design that requires that other variables which may confound the experiment be held constant between the treatment groups, so that any differences in the groups can be attributed to the different treatments.
Randomization
The principle of experimental design that requires that the subjects/experimental units be assigned to groups using some random process. This ensures that the two groups are roughly equal prior to assigning treatments.
Data Collection
The process by which information is gathered from a study.
Peer Review
The process of experts in the field critiquing each other's work in order to make subsequent research more well-done and reliable.
Quality Control
The process of inspecting work for defects or flaws before releasing it to the public.
Which of these statements is true for an experiment? The researcher should have control over all of the variables The researcher should have control over exactly one variable The researcher should not have control over any variable The researcher should have control over some of the variables
The researcher should have control over some of the variables
Statistics
The study of collecting, analyzing, interpreting, and presenting information
Bias
The systematic favoring of certain outcomes in a study. There are many ways to introduce bias into a study.
Which of these random samples represents a representative sample of the systolic blood pressure of all patients in a hospital? The systolic blood pressure of 50 patients in the hospital. The systolic blood pressure of 50 employees in the hospital. The systolic blood pressure of 50 patients in the neurology department. The systolic blood pressure of 50 children admitted in the hospital.
The systolic blood pressure of 50 patients in the hospital.
Bias
The tendency for collected data to differ from what is expected in a systematic way. Biased data can often favor a specific group of those studied.
Which of these statements is false for a completely randomized design? There is only one primary factor under consideration. The test subjects are first broken into groups based on a certain variable of interest before being assigned to each treatment condition The test subjects are assigned to treatment levels of the primary factor at random. This design can lead to random errors
The test subjects are first broken into groups based on a certain variable of interest before being assigned to each treatment condition
Variables of Interest
The variables the survey wishes to measure about those taking the survey.
Wording of Questions
The way in which a question is phrased can influence the response given by the participants in the study.
Experimental Design
The way in which an experiment is carried out. A good design has key elements of randomization, replication, and control.
Survey Design
The way the survey is set up. This deals with wording of questions and answer choices.
Probability Sampling Plan
The way to collect a random sample that guarantees a certain likelihood for each member of the population to be selected
Which of these statements is true regarding a pilot study for an experiment? This study is carried out during the survey to know the estimated duration of the survey. This study generally finds out the margin of error in an experiment. This study is carried out before a survey is conducted. This study is carried out after conducting a survey to get the final results.
This study is carried out before a survey is conducted.
Evaluate whether the statements about sampling is "True" or "False." In order to be valid, a sample should be representative of the population.
True
Raw Data
Unorganized, unprocessed and not summarized. Typically, this is data that is not already available.
Descriptive statistics
Using only the information at hand to describe the selected group of individuals
Inferential statistics
Using the information at hand to make a larger, more general statement about the entire population of individuals
On the survey, Tim has listed various aspects of cell phone service that he wants customers to rank on a scale of 1-9. These include call quality, coverage area, customer service quality, handset selection and variety, and service plan variety. The aspects in the survey, such as call quality and coverage area, are examples of __________ in Tim's survey.
Variables
The manager of a restaurant wants to determine the favorite beef dish among his customers. Which question should the manager use in the survey? Have you ever tried a beef dish in our restaurant? Which item on the menu do you like the most? Do you like beef? Which beef dish do you like the most?
Which beef dish do you like the most?
The manager of an amusement park wants to determine the favorite ride among children. Which question should the manager use in the survey? Which ride do you like the most? When did you last visit the amusement park? Which was the last ride you tried? Have you ever taken a ride on the roller coaster?
Which ride do you like the most?
Tim's draft survey has the question, "Given that people are using cell phones to frequently check email and stay in touch with friends, do you strongly agree that a cell phone is a necessity?" A few people that took the survey mentioned that the question was confusing. Tim decides to simplify the question to, "Is your cell phone a necessity?" The element of survey design that Tim is working on is the survey __________.
Wording of Questions
A poll was conducted two weeks before an election and showed that the incumbent would win with 54% of the vote and a margin of error of 3%. Can there be confidence in the incumbent's victory?
Yes
Data that was gathered for a past study and re-used to answer questions in a present study is called __________ data.
available
Jenae is able to purchase a different brand coffee for half the price from a new supplier. Jenae anticipated that her coworkers would object to switching to the new brand as they were really partial to the coffee they have been drinking so far. Indeed, when offered a taste test of the old brand versus the new brand, her co workers unanimously rejected the new brand. Jenae's boss, Steven, pointed out that this result is most likely due to the fact that the taste test was not ____________. :
blinding
Match each type of sample with a reason for using that approach to sampling. Researchers want to reduce costs by limiting the geographic areas that they take their sample from.
cluster sample
Match each type of experimental design to the corresponding example. George and Naomi create "normal" and "enhanced" versions of their menu, then mix them together thoroughly in a stack. Customers get whichever version of the menu happens to be on the top of the pile. George and Naomi make a note of which menu each person got, what they ordered and what they thought about the menu options.
completely randomized design
A __________ variable is an unforeseen variable that is related to the explanatory variable and has a significant effect on the response variable.
confounding
Jenae noticed that one of the coffee pots was located closer to the coffee cups. She wondered if that influenced her co-workers' choices, causing a result that she did not anticipate. A __________ variable from this example is the location of the coffee pots. :
confounding variable
Tim has looked at the results of the small survey that used his first draft. He finds that the results from teens and elderly people are very different. In Tim's survey, age is an example of a(n) _______________.
confounding variable
Jenae changed the original coffee labels with plain white ones that had the flavor printed in bold black letters, and she placed them on the coffee pots for the week-long experiment. Jenae used an aspect of experimental design known as __________ when she created the labels. :
control group
Match each type of experimental design to the corresponding example. George and Naomi keep an eye out for groups of 2, 4, or 6 individuals that seem very similar to each other. They give half of the group their "normal" menu and half of the group their "enhanced" menu. They keep a record of what each person in the group ordered and then ask them individually why they chose the dish they ordered.
matched pair design
Jenae's study ignored the fact that only some of her coffee choices had caffeine, although her co-workers preferred caffeinated coffee. Jenae decided to label one type of decaf coffee as having caffeine to see what would happen. As she thought, the coffee became more popular with her co-workers, and they claimed that the extra boost of caffeine helped them focus on their work. This result is called the __________.:
placebo effect
Jenae focuses on six different coffee flavors. She wants to see which flavor will prove to be most popular among her coworkers. First she separated the workers into groups according to the department they work in. Then, for each worker, she rolled a die and assigned the coffee flavor according to which number came up. In addition, she made sure that the six flavors are equally represented in each group. Which type of experimental design is used in this situation? :
randomized block design
Match each type of experimental design to the corresponding example George and Naomi prepare two stacks of menus. Each stack contains an equal number of "normal" and "enhanced" menus, all mixed up to be in a random sequence. They reserve one stack for their regulars, and the other stack they use with customers that do not come as frequently. The customer gets whichever menu is on top of the pile that is reserved for their group. George and Naomi keep careful notes about each customer's group, which menu they got, what they ordered, and any comments they made.
randomized block design
Match each type of sample with a reason for using that approach to sampling. Researchers want to ensure that all individuals in the population have an equal chance of being selected.
simple random sample
Match each type of sample with a reason for using that approach to sampling. Researchers want to ensure that particular groups are proportionately represented in the sample.
stratified random sample
The coffee was kept next to Jenae's desk, so she planned on watching her co-workers' throughout the week and collecting data on which type or flavor of coffee they chose. She also observed whether or not they used cream, milk, or nothing and whether or not they used sugar, an artificial sweetener, or nothing. According to statistics, variables such as flavor selected, use of cream, and sweetener selected can also be called :
variables of interest
