Final Flashcards
The entire group of people about which we
wish to generalize
Population
A portion of a population
Sample
Sampling only those who are easy to contact
Convenience sampling
Sampling only those who volunteer
Self-selection
What are the 4 non-probability sampling techniques?
Convenience sampling
Quota sampling
Purposive sampling
Snowball sampling
What are the 4 probability sampling techniques?
Simple random sampling
Systematic sampling
Stratified random sampling
Cluster sampling
Every individual in the population
has an equal chance of being selected
Simple random sample
Sample is selected according to a random starting point and a fixed periodic interval
Systematic sampling
Strata are formed based on members’
shared attributes or characteristics
Stratified random sampling
Uses “natural” but relatively heterogeneous
groupings in a population.
Cluster sampling
An extension of convenience sampling, based on the characteristics of the sample and the purpose of the research
Purposive sampling
Participants are chosen out of specific subgroups that are identified, with convenience sampling used to select the required number of participants from each subgroup
Quota sampling
Participants recruit other participants, used to collect data when the desired sample characteristic is rare, or it is difficult to locate respondents
Snowball sampling
Describes the data (variables) quantitatively
Descriptive statistics
What are the differences between parameters and statistics?
Statistics describe samples, parameters describe populations
A spreadsheet of our variables and their values
Data matrix
A table which provides the number of or
frequency of each possible value
Frequency distribution
A way of providing a graphical representation of the frequency of one variable of interest
Histogram or dot plot
Measure of central tendency that can tell us where most of our scores in our dataset center around
Mean
The middle score that splits the dataset in half
Median
The most common number in a dataset
Mode
What are the two ways to measure spread/variability in data?
Variance and standard deviation
The average spread that each number in our dataset has around the mean
Variance
The square root of the variance which provides a benchmark or indicator of spread for our dataset
Standard deviation
Specify how far away (in standard deviation units) one score is from the mean
Z-score
How does one calculate a z-score?
Difference between the individual score and the mean divided by the standard deviation
A degree of how one variable changes in
relation to the other variable
Covariance
A standardized covariance ranging from -1.0 to +1.0
Pearson’s r
Tell us the strength of a relationship between two variables
Effect sizes
Tells us the distance between the means of two groups in standard deviation units
Cohen’s d
A set of procedures that use the rules of probability to make inferences or generalizations about a population using sample data
Inferential statistics
What are three types of point estimates?
Percentage
Effect size
Strength of relationship
Range around the point estimate that often contains the true value (population value)
Confidence interval
What does the CI for a percentage estimate include?
Percent estimate +/- margin of error
On which three factors does the margin of error vary?
SD
Sample size
Level of confidence
What is the difference between CI and NHST?
CI represents a “new statistics” based on estimation
Null hypothesis significance testing is binary (yes/no)
What do H0 and H1 imply?
H0: Null hypothesis, no effect
H1: Alternate hypothesis, significant treatment effect
Describe the difference between a type l and type ll error
Type l: False positive, reject null hypothesis when it is true
Type ll: False negative, fail to reject null hypothesis when it is false
What hypothesis tests are appropriate for determining the mean difference for two groups?
Independent samples t-test, dependent samples t-test
What characteristics define independent samples t-tests?
Independent groups, between-subjects design
What characteristics define dependent-sample t-tests?
Dependent groups, within-subjects design
What hypothesis tests are appropriate for determining mean differences for two or more groups?
One-way ANOVA, repeated-measures ANOVA, two-way ANOVA
What is the f-ratio?
Between groups variability over within groups variability
What hypothesis test is appropriate for assessing the relationship between two numerical variables?
Pearson correlation: Correlation coefficient r and measure of effect r squared
Printed instruments that the respondents complete
Paper and pencil questionnaires
Online surveys created as Web forms with a database to store the answers
Electronic (e-surveys)
Respondents complete questionnaires that are completed on paper and returned via mail
Mail surveys
Collecting data using a telephone to contact respondents
Telephone surveys
Collecting data using a variation
of the different survey methods
Mixed-mode surveys
Collecting data face to face
Interviews
Questions that allow people to provide detailed answers.
Open-ended questions
Questions provide a limited selection of available responses.
Forced-choice questions
Questions use a rating scale to indicate level of agreement
Likert scale
Questions provide a numeric scale anchored by adjectives
Semantic differential
Which types of questions are appropriate for nominal measurements?
Dichotomous, demographic, forced choice
What types of questions are appropriate for ordinal measurements?
Rank order, scales, and likert-type
What types of questions are appropriate for interval measurements?
Semantic differential
Questions that require answers for two different options, leading to confusion
Double-barreled
Questions worded in such way that they imply a derogatory association
Negatively-worded questions