hlth-2305
In a study of how college students give directions from maps, 40 Introductory Psychology volunteers, 20 men and 20 women, were given the task of giving directions to another. Observations were made of subjects' direction-giving behavior in the experiment: (a) the sex of the direction giver (b) the distances given as part of the directions (c) the number of times directions such as North, Southwest, etc. were used For each of the variables in this experiment, determine whether it is categorical or numerical. For each numerical variable, determine whether it is discrete or continuous
A. Categorical B. Numerical, continuous C. Numerical, discrete
Identify the data classification for the following statement: Data that is collected that represents sales by store number and by location
Bivariate
One of the tasks of wildlife biologists is to estimate bird populations. One method for doing this is to walk a "transect," typically a long randomly selected rectangle, and count the number of particular species that are seen. During hunting season the biologists wear brightly colored clothes as a protective measure. A theory, known as the "species-confidence hypothesis," predicts that birds may react to these brightlycolored clothes. A robin, for example, when confronted with a biologist wearing an orange color may be less afraid than if the biologist were wearing a brown color. The idea is that the orange color gives the robin some "confidence" that the biologist is another (really big!) bird. This is a difficulty because a robin that is less afraid of the biologist may be easier to see and therefore "count" because the robin lets thebiologist get closer. This would result in too high an estimate of the robin population. To test this theory a biologist performed a study in her area, wearing a bright orange vest or a brown vest while working. After training herself to accurately estimate distances she indicated on her notes how close the robins would let her get before they flew away (the "approach distance"), using this as a measure of their"confidence." She randomly selected her starting points in each trip through the transects and also carefully noted the weather conditions, specifically the wind speed. What is the Explanatory variable for this study?
The coloration of the vest (bright orange vs brown) the biologist wears
Reasons for studying statistics are:
Understanding and Making Decisions Decide such as deciding if existing information is adequate or decide whether to collect more information in an appropriate way
One of the tasks of wildlife biologists is to estimate bird populations. One method for doing this is to walk a "transect," typically a long randomly selected rectangle, and count the number of particular species that are seen. During hunting season the biologists wear brightly colored clothes as a protective measure. A theory, known as the "species-confidence hypothesis," predicts that birds may react to these brightlycolored clothes. A robin, for example, when confronted with a biologist wearing an orange color may be less afraid than if the biologist were wearing a brown color. The idea is that the orange color gives the robin some "confidence" that the biologist is another (really big!) bird. This is a difficulty because a robin that is less afraid of the biologist may be easier to see and therefore "count" because the robin lets thebiologist get closer. This would result in too high an estimate of the robin population. To test this theory a biologist performed a study in her area, wearing a bright orange vest or a brown vest while working. After training herself to accurately estimate distances she indicated on her notes how close the robins would let her get before they flew away (the "approach distance"), using this as a measure of their"confidence." She randomly selected her starting points in each trip through the transects and also carefully noted the weather conditions, specifically the wind speed. What is a possible confounding variable for this study?
Wind Velocity on a windy day while this study is conducted
Match the definition with the sampling technique: stratified- D cluster- B systematic- C convenience- E random- A
A. Consist of availabale members of a population and often leads to biased results B.Members of the population are divided into catagories or strata made up of age, ethnicity, sex, religion, etc C.members selected from geographical zones such as zip code, counties, cities, etc D.Members selected by a process such as every 50th person listed in a phone book E.Every member of a population has an equal chance of being selected
Determine which of the following statements is descriptive and inferential and types of variables (categorical and numerical) for the stated questions: B) The average age of 500 surveyed students at Stockton C) Based on a sample of 10,000 Americans, it is fair to say that 70% are overweight A) Based on a sample survey of car owners, we are interested in variables that represent the type of vehicle owned (Toyota, Honda, Ford, etc) D) Based on a sample survey of car owners, we are interested in the value (in dollars) of each car owned by persons in the survey
A. Descriptive B. Inferential C. Numerical Type Data D. Categorical Data
Match the experimental design concept to the appropriate definition: Blocking Replication Single Blinded Control Group Placebo
Blocking- A. A process by which extraneous variable effects are filtered out by creating groups that are similar. All experimental conditions (treatments) are then tied to this process Replication- B. A process to ensure that there is an adequate number of observations or multiple observations for each experimental condition Single Blinded- C. An experiment in which subjects do not know what treatment they have received but the individuals measuring the response do know Control Group- D. A process where-by this is established to allow the experimenter to contrast how the response variable behaves when treatment is not used. This provides a baseline for comparison. Placebo- E. A process where-by administration of this involves something that is identical to the treatment group but contains no active ingredient
One of the tasks of wildlife biologists is to estimate bird populations. One method for doing this is to walk a "transect," typically a long randomly selected rectangle, and count the number of particular species that are seen. During hunting season the biologists wear brightly colored clothes as a protective measure. A theory, known as the "species-confidence hypothesis," predicts that birds may react to these brightlycolored clothes. A robin, for example, when confronted with a biologist wearing an orange color may be less afraid than if the biologist were wearing a brown color. The idea is that the orange color gives the robin some "confidence" that the biologist is another (really big!) bird. This is a difficulty because a robin that is less afraid of the biologist may be easier to see and therefore "count" because the robin lets thebiologist get closer. This would result in too high an estimate of the robin population. To test this theory a biologist performed a study in her area, wearing a bright orange vest or a brown vest while working. After training herself to accurately estimate distances she indicated on her notes how close the robins would let her get before they flew away (the "approach distance"), using this as a measure of their"confidence." She randomly selected her starting points in each trip through the transects and also carefully noted the weather conditions, specifically the wind speed. Is this type of study an observation or experiment?
Both and Observation and Experiment
In a psychological study of distance perception, introductory psychology class volunteers were given 5, 10, or 15 extra credit points depending on their level of participation in the experiment. They walked along paths laid out along hallways in the psychology building, and were asked to judge the distance they had walked. Each path distance was between 100 and 200 feet in length, and contained from two to seven 90 degree turns. The investigators also kept track of class standing (freshman, sophomore, junior, or senior). For each of the variables in this study, determine whether it is categorical or numerical. For each numerical variable, determine whether it is discrete or continuous
Class Standing- A. Categorical The true length of the path- B. Numerical, continuous The amount of credit given to the volunteers- C. Numerical, discrete
A condition that occurs in an experiment when the experimenter is not able to distinguish between the effects of different factors is referred to as
Confounding
Identify the data sampling technique that is used in this experimental design: A journalist goes to a beach to ask people how they feel about water pollution
Convenience
Which of the following is a population? A. All of the students within this particular statistics class B. All of the registered voters in the state of New Jersey for the New Jersey Gobernatorial Election C. Three people randomly selected from a group D. All of the above E. None of the above
D
An experiment is conducted where treatment to cure the common cold is given to patients. The patients are divided into two groups where one set of patients is provided the real treatment and the other group is given a placebo. A condition where neither the subjects nor the individuals who measure the response knows which treatment is received is known as
Double Blinded Experiment
Variables that have values that are controlled by the experimenter (also called factors)
Explanatory variable
A Variable that is not one of the explanatory variables but is thought to affect the response of an experiment or study
Extraneous variable
There is a relationship between smoking cigarettes and getting emphysema. Does this statement describe inferential statistics or discriptive?
Inferential
One part of the Demographic and Health Surveys Program is concerned with measures of malnutrition. Investigators measure physical aspects of growing children, and attempt to document the physical characteristics of a population at different ages. Sadly, in some countries many children die early, and thus a bias is introduced in the study when the investigators can not collect the data from the deceased children. What type of Bias is exhibited in this study?
Nonresponse bias
A study was conducted: Before the opening of the new International Airport and the termination of the old airport, children near both sites were recruited into aircraft-noise groups (aircraft noise at present or pending) and control groups with no aircraft noise and closely matched for socio-economic status. A total of 326 children (mean age = 10.4 years) took part in three data-collection waves, one before and twoafter the switch-over of the airports. After the switch to the new airport, longterm memory and reading were found to be impaired in the noise group at the new airport, and improved in the formerly noise-exposed group at the old airport Is this type of study an observation or experiment?
Observation
Match the definitions with the terms associated with observations and experiment type studies: Observation Type Study Experiment Type Study Explanatory Variable Extraneous Variable
Observation Type Study- A. The researchers do not manipulate any factors. Instead, they observe characteristics of a subset of the members of one or more existing populations. Experiment Type Study- B. Researchers observe how a response variable behaves when they manipulate one or more factors Explanatory Variable- C. Is the varaible that researchers manipulate in order to observe changes in the response variable Extraneous Variable- D. Is any other variable which is thought to affect the response variable, but is not of interest in the study
The likelihood that an animal will successfully avoid a predator's attack should increase if the presence of the predator is detected. Animals are, of course, known to warn others of a predator's presence - the well-known prairie-dog warning call is an example. Some aquatic animals are known to send chemical signals. For example the crayfish and Iowa darter may excrete ammonium from their gills or possibly intheir urine during periods of heightened metabolic activity. In an experiment to see if red-legged frogs (Rana aurora) may send or respond to chemical signals, specimens in Oregon were collected as embryos and raised in an aquarium. As tadpoles they were separated into two pairs of aquaria. The "upper tank" in each pair was connected to the "lower tank" to create a (very!) small river. A wooden heron model was placed in one of the upper tanks and moved around for 30 seconds to simulate a predator attack. Both the sender (upper tank) and receiver (lower tank) animals were monitored for added activity (increased movement) indicating antipredator behavior. What is the explanatory variable (factor) for this experiment?
Presence/absence of the wooden heron model
The likelihood that an animal will successfully avoid a predator's attack should increase if the presence of the predator is detected. Animals are, of course, known to warn others of a predator's presence - the well-known prairie-dog warning call is an example. Some aquatic animals are known to send chemical signals. For example the crayfish and Iowa darter may excrete ammonium from their gills or possibly intheir urine during periods of heightened metabolic activity. In an experiment to see if red-legged frogs (Rana aurora) may send or respond to chemical signals, specimens in Oregon were collected as embryos and raised in an aquarium. As tadpoles they were separated into two pairs of aquaria. The "upper tank" in each pair was connected to the "lower tank" to create a (very!) small river. A wooden heron model was placed in one of the upper tanks and moved around for 30 seconds to simulate a predator attack. Both the sender (upper tank) and receiver (lower tank) animals were monitored for added activity (increased movement) indicating antipredator behavior. What is the Response variable for this experiment?
Red legged frogs behavior to the simulated attack
One part of the Nurses' Health Study is concerned with possible causes of skin cancer. Nurses were asked about different behaviors and aspects of their health when they entered the study. Then, the nurses were given the questionnaire again if they were diagnosed with cancer. When the questionnaires were analyzed, the investigators discovered that after the nurses were diagnosed with cancer they tended to report areduced ability to tan. It is thought that the shift in reporting might be caused by an awareness of their diagnosis. What type of Bias is exhibited in this study?
Response bias
A variable that is not controlled by the experimenter and that is measured as part of the experiment or study is referred to as
Response variable
At a large community college, 120 students are randomly selected and asked the distance of their commute to campus. For this group aa average of 9.8 miles is computed. Match the items in column II with the statistical terms in column I Sample Experiment Population Statistics Sample Point
Sample- B. The 120 students that are randomly selected Experiment- C. The process used to select the 120 students and determine distance traveled Population- D. All students enrolled at the college Statistics- A. the computed average of 9.8 miles Sample Point- E. The commute distance of 13 for student number 94
Identify the data sampling technique That is used in this experimental design: A researcher randomly selects and interviews fifty male and fifty female teachers
Stratified
One of the tasks of wildlife biologists is to estimate bird populations. One method for doing this is to walk a "transect," typically a long randomly selected rectangle, and count the number of particular species that are seen. During hunting season the biologists wear brightly colored clothes as a protective measure. A theory, known as the "species-confidence hypothesis," predicts that birds may react to these brightlycolored clothes. A robin, for example, when confronted with a biologist wearing an orange color may be less afraid than if the biologist were wearing a brown color. The idea is that the orange color gives the robin some "confidence" that the biologist is another (really big!) bird. This is a difficulty because a robin that is less afraid of the biologist may be easier to see and therefore "count" because the robin lets thebiologist get closer. This would result in too high an estimate of the robin population. To test this theory a biologist performed a study in her area, wearing a bright orange vest or a brown vest while working. After training herself to accurately estimate distances she indicated on her notes how close the robins would let her get before they flew away (the "approach distance"), using this as a measure of their"confidence." She randomly selected her starting points in each trip through the transects and also carefully noted the weather conditions, specifically the wind speed. What is the response variable for this study?
The approach distance of how close the robin flys to the biologist
