Ch.1 Stats

Observational Sampling:

Representative sample

sample statistic

a number that describes a characteristic of a sample

experiment

o Generates data to help identify cause effect relationships

identify a sampling technique for following study: A pollster chooses twenty people at random from each math class.

stratified sampling

meta-analysis

study that compiles info from previous studies

single-blind

subjects dont know, but experimenters do

placebo

substance that looks identical to actual treatment

identify the sample: The number of hours a group of 11 children in Mrs. Smith's kindergarten class watch television in a day.

the 11 children selected in Mrs. Smith's kindergarten class

Descriptive Statistics

"just the facts" sample data about a population w/o assumptions abt population

Level orders of measurement

1. Nominal 2. Ordinal 3. interval 4. ratio

sample statistic example

100 college students are chosen and 42% do laundry

population parameter example

76% of all college students own a laptop

Two types of Quantative Data

Continuous and Discrete

descriptive or inferential: The average price of a car at the new car dealership in town is $28,200

Descriptive Statistic

IQ scores, reported in whole numbers, of research scientists are an example of which type of data? (cont or desc)

Discrete

Random Sample

Every member of the population has an equal chance of being selected

Systematic Sampling

Every nth member of the population is chosen

Ordinal Example

Excellent, average, poor

When working with humans or animals, the ____ requires extensive proof that no physical or mental harm will occur to the subjects in the study.

Institutional Review Board

Indicate the level of measurement for the data set described. Number of class meetings in a term at various schools

Interval

Nominal Example

Maeve belongs in the second grade

Discrete and continuous are both what type of data

Quantitative

Football jersey numbers are an example of which type of data?

Quantitative

Sampling Methods

Random Sampling, Simple Random sampling, stratified sampling, cluster sampling, systematic sampling, convivence sampling

Parameter or statistic: A survey of 3159 people in the U.S. revealed that 73% of those surveyed are self-conscious about their weight.

Sample Statistic

Convivence Sampling

Sample is chosen b/c it is convenient for researcher

Stratified Random Sample

a few members from each group are randomly chosen

identify the population: The number of hours a group of 15 children in Mrs. Smith's kindergarten class sleep in a day.

all children in Mrs. Smith's kindergarten class

Cluster Sample

all members from a few randomly chosen clusters (or groups) are selected

Continuous Data

any value in a given range

Classify the following scenario as a meta-analysis or a case study. Fifteen cattle are selected and examined for signs of disease.

case study

meta-analysis or a case study: Fifteen fish caught in a bay are measured to determine the overall health of the fish in the bay.

case study

difference between meta analysis and case study

case study is singular (detailed description of a single thing) while meta analysis is an analysis of several sources concerning a single thing

Identify the sampling technique used for the following study. For budget purposes, a financial advisor needs to know the average salary of instructors at their school.

census

Identify the sampling technique used for the following study. Select each member of the entire sampling frame.

census

Identify the sampling technique used for the following study. A pollster interviews each member from each of the five randomly chosen neighborhoods throughout a city.

cluster sampling

Identify the sampling technique used for the following study. A random number generator is used to choose twenty-five zip codes. Then a biologist collects data from each person in these zip codes.

cluster sampling

Identify the sampling technique used for the following study. A statistics student interviews each member from each of the ten randomly chosen zoning districts in a town.

cluster sampling

Temperatures in Kelvin of various sites on the moon are an example of which type of data? (cont or descr)

continuous

Types of Observational Studies

cross-sectional study, longitudal, meta-analysis, case studies

longitudinal Study

data gathered over periods of time

Determine whether the statement describes a descriptive or inferential statistic. 63% of all freshmen at your school reside on campus.

descriptive statistic

The numbers of TV shows taped in Los Angeles on various days are an example of which type of data? (cont or descrete)

discrete

Cofounding Variables

factors other than the treatment that cause an effect

qualitative data example

foods, hometown

treatment group

has an applied treatment

Determine whether the statement describes a descriptive or inferential statistic. A recent poll of 3505 home owners in Indiana showed that the average price of a house in the U.S. is $⁢339,000.

inferential statistic

descriptive or inferential statistic: A survey of 3459 people revealed that 52% work a full-time job; therefore it can be assumed that 52% of the U.S. population works a full-time job.

inferential statistic

inferential statistics

interpretation of collected information

Indicate the level of measurement for the data set described. Temperatures (in degrees Celsius) of various sites on the planet Saturn

interval

identify level of measurement: Copyright years of all books in a library

interval

double blind

neither subjects nor experimenters know

Control group

no applied treatment

Identify level of measurement: Favorite category of movies reported in a survey

nominal

Indicate the level of measurement for the data set described. Preferred cellphone brands of AT&T customers

nominal

Qualitive levels of measurement

nominal, ordinal

population parameter

numbers that describe a population

observational study

o Observes data that already exists

ordinal

o Qualitative o Can be arranged in a meaningful order/ natural order o Calculations still do not make sense

ratio

o Quantitative o Differences b/t data entries are meaning, zero point indicates absence of something

Discrete Data

only particular values, no in between

Identify level of measurement: Letter grades given for a college course

ordinal

Indicate the level of measurement for the data set described. Karate belt colors worn by members of a martial arts gym

ordinal

difference between nominal and ordinal:

ordinal has an order to qualitative data, while nominal does not

Discrete Data example

people population, how many pets you own

identify population and sample: The heights of 4 out of the 36 pepper plants at Mr. Lonardo's greenhouse.

pop: the 36 pepper plants at Mr. Lonardo's greenhouse Sample: The 4 pepper plants at Mr. Lonardo's greenhouse

population or sample: The price of homes of all the employees at a software company.

population

Indicate the level of measurement for the data set described. Number of athletes on the roster of each football team in the NCAA

ratio

Indicate the level of measurement for the data set described. Total dollar value of all items in a safe

ratio

Identify the sampling technique used for the following study. First, the population is subdivided by city. Then a college student uses a random number generator to select ten members from each city to study.

stratified sampling

Identify the sampling technique used for the following study. First, the population is subdivided by city. Then a quality assurance analyst uses a random number generator to select twenty-five members from each city to study.

stratified sampling

Quantative data example

length, width

identify level of measurement: Number of siblings that students in your statistics class have

ratio

difference between interval and ratio:

ratio data has a defined zero point (income). zero on a interval data does not have a true zero (time)

placebo effect

response to power of suggestion, not the treatment itself

population or sample: The heights of 1414 out of the 3131 cucumber plants at Mr. Lonardo's greenhouse.

sample

parameter or statistic: A recent poll of 3787 home owners in Pennsylvania showed that the average price of their houses is $317,000

sample statistic

Observational Study Example

scores, colors

Quantative data

Counts or measurements

Simple Random Sample

Every sample of the population has an equal chance of being selected

Interval Example

Temperature being calculated and interpreted

Select the term which best describes the following scenario. A new painkiller is studied. A group of people with chronic pain participating in the study are administered the drug. It is not identified prior to the study what is causing their pain, and the source of their pain impacts their response to the drug.

cofounding variable

Quantitative levels of measurement

interval, ratio

nominal

labels and names, NO calculations can be performed

Qualitive data

labels or descriptions

Continuous Data example

length, width

case study

looks at multiple variables that affect a single event

Classify the following scenario as a meta-analysis or a case study. An underwriter compares ten weather reports from hurricanes to compare for common factors.

meta-analysis

meta-analysis or a case study: A police chief compares five newspaper articles about crime prevention.

meta-analysis

interval

o Quantitative o Can be ordered, however is disguised b/c differences b/t data entries are meaningful o Comparing and ordering

observational or experimental: A general manager of a restaurant wants to study the number of cars passing a billboard in a day.

observational

Select the term which best describes the following scenario. A study is done an a new drug designed to lower blood pressure. Individuals with high blood pressure are selected for the study and some are given pills containing the drugs while others are given pills that do not contain any of the drug. Even the group which did not take the drug sees an improvement in their blood pressure. What could be causing this?

placebo effect

parameter or sample statistic: The average number of hours students in your statistics class study per week is 12.2

population parameter

Hair colors are an example of which type of data? (qual or quant)

qualitative

Types of movies people go to see are an example of which type of data? (qual or quant)

qualitative

Amounts of yearly rainfall in Miami over the last 55 years are an example of which type of data?

quantitative

Pounds gained by persons in your class during the first month of the semester are an example of which type of data? (qual or quant)

quantitative

In a ____ experiment, only the subject does not know whether they have been placed in the control or experimental group.

single-blind

Identify the sampling technique used for the following study. A market researcher chooses fifty people at random from each neighborhood.

stratified sampling