Exam 2 Review - Research Methods in Psychology

Self-Report Measures

A method of measuring a variable in which people answer questions about themselves in a questionnaire or interview.

What is an example of a Self-Report measure?

Dr. Diener’s five-item questionnaire on happiness

Observational Measures

A method of measuring a variable by recording observable behaviors or physical traces of behaviors (also called behavioral measures)

What is an example of Observational Measures?

How long it takes a participant to press a button in response to a stimulus (i.e., response times, usually in milliseconds)

Physiological Measures

Method of measuring a variable by recording biological data (ex. fMRI, EEG, skin conductance, etc)

Categorical Variable

A variable whose levels are categories and don’t have a meaningful numeric value. Levels are qualitatively distinct.

Quantitative Variable

A variable whose values can be recorded as meaningful numbers

Nominal Scale

A categorical variable without a meaningful ordering (religious affiliation; breakfast cereals; personality type)

Ordinal Scale

A categorical variable with meaningful ordering (rank in a jumping contest; highest degree earned)

Interval Scale

Numerals represent equal distances between levels and there is no true zero point (zero does not mean “nothing”)

Ratio Scale

Numerals represent equal intervals and there is a true zero (zero means there is nothing)

Reliability

How consistent the results of a measure are

Test-retest Reliability

Consistent scores every time the measure is used

Interrater Reliability

Consistent scores no matter who does the measuring

Internal Reliability

A participant provides a consistent pattern of responses, regardless of how the researcher has phrased a question

Researchers will often use ___ and ___ to assess reliability

scatterplots; correlation coefficients

To see if a scale (i.e., measure) has test-retest reliability:

We test the same group of individuals twice, a few weeks or months apart

The “strength” of a relationship refers to how ___ or the

___ of a relationship between two variables is

consistent; magnitude

We can numerically describe the ___ (positive or negative association) and ___ of a linear relationship. This is called the ___

direction; strength; correlation coefficient

A positive correlation coefficient =

positive association

A negative correlation coefficient =

negative association

The absolute value of the coefficient refers to the ___ of the relationship

magnitude

Face Validity

The extent to which a measure is subjectively considered a plausible operationalization of the conceptual variable in question

“Do the items on this survey LOOK like depression items?”

Content Validity

The extent to which a measure captures all components of a defined construct

“Do these items in the survey get at all the components of depression?”

Criterion Validity

An empirical form of measurement validity that establishes the extent to which a measure is associated with a behavioral outcome with which it should be associated

Convergent Validity

The extent to which the measure is related to other measures assessing the same construct

If the measure is valid, we expect it to correlate or converge with other measures of the same thing

Discriminant Validity

The extent to which the measure is not related to other measures designed to assess different, unrelated constructs

If the measure is valid, we expect it to be uncorrelated with things that are likely confounds

Likert Scale

People are presented with a statement and asked to use a rating scale to reflect their degree of agreement.

Example: “I am able to do things as well as most other people” (1-5)

Semantic Differential Format

Respondents asked to rate a target object using a numeric scale anchored by adjectives

Example: “Level of Difficulty of Class” (1-5)

Leading Questions

A type of question in a survey that is problematic because its wording encourages one response more than others, thereby weakening construct validity

Double-barreled Questions

Asking two questions in one

Negatively Worded Questions

Contains negatively phrased statements, making its wording complicated or confusing and potentially weakening construct validity

“People who do not drive with a suspended license should never be punished”

Acquiescence Bias

Answering “yes” or “strongly agree” to every item

Fence Sitting

Playing it safe by answering in the middle of the scale for each item

Observer Bias

When observers’ expectations influence their interpretations of participants’ behaviors or the outcome of the research

Observer Effects

When observers change the behavior of the participants to match the observer’s expectations

Example: Bright vs dull rats. Students given rats and told that they were either dull or bright. This influenced how quickly the rats completed the maze

Masked Design

The observers do not know to which conditions the participants have been assigned, and they are not aware of what the study is about

The number of people in the sample determines the magnitude of sampling ___

error

Suppose we want to know how important USF students think physical exercise is for wellbeing.

If we randomly sample 10 students then we are more like to have higher sampling error than if we sampled 100 students

The way people are chosen determines the magnitude of sampling ___

bias

Suppose we want to know how important USF

students think physical exercise is for well-

being.

If we will have more sampling bias if we sample

people as they exit the gym than if we did a truly

random sample

Systematic Sampling

Selecting individuals within the defined population from a list by taking every Kth name (item on the list)

For example, I took the roster from the class, where people are listed alphabetically and I gave each person a number

I randomly pick two numbers between 1-10 (say, 4 and 5)

I start with person 4 and then pick every 5th person

Cluster Sampling

Clusters of participants within a population of interest are randomly selected, and then all individuals in each cluster are used

Multistage Sampling

Two random samples are collected

• Stage 1: A random sample of clusters is selected

• Stage 2: For the selected clusters, a random sample of people is chosen

Random Sampling

Creating a sample using some random method so that each member of the population of interest has an equal chance of being in the sample

Increases external validity

Random Assignment

Only used in experiments; participants are randomly put into different groups after sampling has occurred. Increases internal validity.

Snowball Sampling

A variation on purposive sampling, a biased sampling technique in which participants are asked to recommend acquaintances for the study

sampling error

the amount of inaccuracy in estimating some value that is caused by measuring only a portion of a population rather that the whole population

Sampling Bias

nonrandom differences, which cause the sample to overrepresent (or underrepresent) individuals or groups within the population