pysch honors exam 2

null hypothesis

the hypothesis that an effect or relationship does not exist (or exists in the opposite direction of the alternative hypothesis) in the population.

critical region

the most extreme portion of a distribution of statistical values for the null hypothesis, determined by the alpha level (typically 5%)

scientific/alternative hypothesis

the hypothesis that an effect or relationship *does* exist (or exists in a specific direction) in the population.

significant test

the *p-*value is less than or equal to alpha in an inferential test, and the null hypothesis can be rejected.

power

the ability of a significance test to detect an effect or relationship when one exists (equal to 1- the probability of a type II error).

*t* test

significance test used to compare means

one-sample *t* test

used to measure an effect when the population mean without the treatment is known and is compared with a single sample.

independent samples *t* test

used to measure an effect when two samples of different individuals are compared.

between-subjects variable

each participant experiences only one level of the independent variable.

quasi-independent/subject variable

variable that allows comparison of groups of participants without manipulation (i.e., no random assignment), often with characteristics like gender or race.

homogeneity of variances

assumption of between-subjects *t-*tests and ANOVAS that the variance in the scores in the population is equal across groups.

repeated measures/paired samples *t* test

used to measure an effect when two related samples or two sets of scores from the same individual are compared

within-subjects variable

each participant experiences all levels of the independent variable

ANOVA

 an inferential test used for designs with three or more sample means; used to measure an effect when more than two samples or sets of scores from the same individual are compared

multivalent variable

an independent variable that includes three or more levels- a design is considered multivalent if there is only one independent variable that contains three or more levels

factorial design

an experiment or quasi-experiment that includes more than one independent variable

main effect (ANOVA)

a test of the differences between all means for each level of an independent variable in an ANOVA

post hoc tests

additional significance tests conducted to determine which means are significantly different for a main effect

interaction effect (ANOVA)

tests the effect of one independent variable at each level of another independent variable in an ANOVA

pearson *r* test

a significance test used to determine whether a linear relationship exists between two variables measured on *interval or ratio scales.*

chi-square test

a significance test used to determine whether a relationship exists between two variables measured on *nominal or ordinal scales.*

regressoion

used to measure a relationship when you want to predict an individual’s score on one variable from the score on a second, related variable

linear regression

a statistical technique that determines the best fit line to a set of data to allow prediction of the score on one variable from the score on another variable

alpha level

 the probability level used by researchers to indicate the cutoff probability level (highest value) that allows them to reject the null hypothesis

degrees of freedom

number of scores that can vary in the calculation of a statistic.

type I error

an error made in a significance test when the researcher rejects the null hypothesis when it is actually true

counterbalancing

a control used in within-subjects experiments where equal numbers of participants are randomly assigned to different orders of the conditions

sphericity assumption

assumption of the repeated measures (within-subjects) ANOVA that pairs of scores in the population have equal variance (similar to homogeneity of variance)

dr wrobel

clinical psychologist who specializes in testing/assessment

survey research

a research study that uses the survey observational technique to measure behavior.

descriptive/predictive

most survey research uses _____ research questions

descriptive research question

a research question that asks about the presence of a behavior, how frequently it is exhibited, or whether there is a relationship between different behaviors

predictive research question

a research question that asks if one behavior can be predicted from another behavior to allow predictions of future behavior

causal research questions

ask what causes specific behaviors to occur

psychometrics

 an area of psychological research that involves the development, validation, and refinement of surveys and tests for measuring psychological constructs

open-ended response scale

participants respond to survey questions in any manner they feel is appropriate for the question

qualitative analysis

organized coding of open-ended, non-numerical responses

close-ended response scale

 participants respond to survey questions according to the response options provided by the researcher

construct validity

indicates that a survey measures the behavior it is designed to measure.

double-barreled question

including two questions in one survey item

leading question

a question in a survey that is worded in such a way as to bias the respondent’s answer

face validity

on the surface, a study or scale appears to be intuitively valid

factor analysis

 a set of statistical techniques to analyze responses from a survey or questionnaire to group items together by concept; can help to determine whether there are too many questions about one topic. 

coverage error

a sampling error that occurs when the sample chosen to complete a survey does not provide a good representation of the population

nonresponse answers

a sampling error that occurs when individuals chosen for the sample do not respond to the survey, biasing the sample.

criterion-related validity

determining the validity of the scores of a survey by examining the relationship between the survey scores and other established measures of the behavior of interest

social desirability bias

bias created in survey responses from respondents’ desire to be viewed more favorably by others, typically resulting in overreporting of “positive” behaviors and underreporting of “negative” behaviors

test-retest reliability

indicates that the scores on a survey will be similar when participants complete the survey more than once (made difficult due to attrition/mortality and testing effects)

attrition/mortality

occurring when participants are unable or choose not to continue a study

testing effects

which can occur when participants are tested more than once in a study, where early testing affects later testing

internal consistency

a form of reliability that tests relationships between scores on different (but similar) items on a survey

split-half reliability

a method of testing scores’ internal consistency that indicates if the scores are similar on different sets of questions on a survey that address similar topics

cronbach’s alpha

a method of testing scores’ internal consistency that indicates the average correlation between scores on all pairs of items on a survey

correlational study

a type of research design that examines the relations between multiple dependent variables, without manipulating any of the variables.

predictor variable

the dependent variable in a correlational study that is used to predict the score on another variable

outcome/response variable

the dependent variable in a correlational study that is being predicted by the predictor variable

scatterplot

 a graph showing the relationship between two dependent variables for a group of individuals

third variable problem

the presence of extraneous/confounding factors in a study that affect the dependent variable and can decrease the internal validity of a study

positive relationship

a relationship between variables characterized by an increase in one variable that occurs with an increase in the other variable

negative relationship

a relationship between variables characterized by an increase in one variable that occurs with a decrease in the other variable

doctor hymes

social psychologist who is particularly knowledgeable about IRB processes and a lot of work in areas of prejudice and stereotyping.

doctor mcaulsan

health/social psychologist interested in the intersections of social, interpersonal, and health psychologies, with history in social support systems, disclosure, interpersonal violence, and sexual assault/harassment reporting.

experiment

a type of research design that involves the manipulation of an independent variable, allowing control of extraneous variables that could affect the results

small-n design

 an experiment conducted with one or a few participants to better understand the behavior of those individuals (like a case study)

independent variable

 a variable in an experiment that is manipulated by the researcher such that the levels of the variable change across or within subjects in the experiment

levels of the independent variable

different situations or conditions that participants experience in an experiment because of the manipulation of the independent variable.

confounding variable

an extraneous factor present in a study that may affect the results.

order effects

occur when the order in which the participants experience conditions in an experiment affects the results of the study

random assignment

participants are randomly assigned to levels of the independent variable in an experiment to control for individual differences as an extraneous variable

matched-pairs design

a between-subjects experiment that involves sets of participants matched on specific characteristics with each member of the set randomly assigned to a different level of the independent variable

latin square

a partial counterbalancing technique where the number of order of conditions used is equal to the number of conditions in the study

doctor clark-foos

cognitive psychologist with a particular interest in perception, memory research (specifically long-term), language, problem-solving, pain, and plagiarism.

sampling error

the difference between the observations in a population and in the sample that represents that population in a study

descriptive statistics

measures that help us summarize and describe data sets

inferential statistics

 a set of statistical procedures used by researchers to test hypotheses about populations

distribution

a set of scores

central tendency

a representation of a typical score in a distribution

mean

the calculated average of the scores in a distribution (most common measure of central tendency)

median

the middle score in a distribution, such that half of the scores are above and half of the scores are below

mode

the most common score in a distribution

outliers

extreme high or low scores in a distribution

reaction time

measurement of the length of time to complete a task

variability

the spread of scores in a distribution.

range

the difference between the highest and lowest scores in a distribution (tends to be a very crude measure of variability)

standard deviation

a measure representing the average difference between the scores and the mean of a distribution

variance

the standard deviation of a distribution squared

degrees of freedom

the number of scores that can vary in the calculation of a statistic

frequency disribution

a graph of a distribution showing the frequency of each response in the distribution

bar graph

a graph of the means for different conditions in a study where each mean is graphed as a point and the points are connected in a line to show difference between mean scores

two-tailed hypothesis

both directions of an effect or relationship are considered in the alternative hypothesis of the test

one-tailed hypothesis

only one direction of an effect or relationship is predicted in the alternative hypothesis of the test

distribution of sample means

the distribution of all possible sample means for all possible samples from a population

confidence interval

a range of values that the population mean likely falls into with a specific level of certainty

alpha level

the probability level used by researchers to indicate the cutoff probability level (highest level) that allows them to reject the null hypothesis

*p* value

probability value associated with an inferential test that indicates the likelihood of obtaining the data in a study when the null hypothesis is true

type II error

an error made in a significance test when the researcher fails to reject the null hypothesis when it is actually false.

factorial design

an experiment or quasi-experiment that includes more than one independent variable

marginal means

average mean scores for each level of an independent variable

simple effects tests

statistical tests conducted to characterize an interaction effect when one is found in an ANOVA

quasi-experiment

a type of research design where a comparison is made, as in an experiment, but no random assignment of participants to groups occurs