PSY200-Research Methods Exam #2

Internal Validity

The ability to draw conclusions about casual relationships from the results of a study

Temporal precedence

Part of casual interference; the cause occurs before the effect

Covariation of cause and effect

Part of casual interference; observing that a change in one variable is accompanied by a change in a second variable

Eliminate plausible alternative explanations

Part of casual interference; based on the possibility that some confounding third variable is responsible for the observed relationship.

Field Experiment

Independent variable is manipulated in a natural setting

Participant variables

Characteristics of individuals, such as age, gender, ethnic groups, nationality, birth order, personality, or marital status. (cannot be manipulated)

Reliability

Refers to the consistency or stability of a measure

True score

Someone's real “true” value on a given variable.

Measurement error

Difference between a true score and a measured score

Pearson product-moment correlation coefficient

Pearson correlation coefficient can range from 0.00 to +1.00 and 0.00 to -1.00. (Closer to 0=not related, closer to +1 or -1=stronger relationship

Test-Retest reliability

Measuring the same individuals at two points in time.

Alternate forms Reliability

Administering two different forms of the same test to the same individuals at two points in time. (Alternate forms reliability)

Internal consistency reliability

Assessment of reliability using responses at only one point in time (Internal consistency reliability)

Split-half reliability

Correlation of the total score on one half of the test with the total score on the other half.

Cronbach’s alpha

Provides the average of all possible split-half reliability coefficients

Item-total correlations

Examine the correlation of each item score with the total score based on all items.

Interrater reliability

The extent to which raters agree in their observations

Construct validity

Refers to the adequacy of the operational definition of variables

Face validity

Measure appears to assess the intended variable accurately

Content validity

Based on comparing the content of the measure with the universe of content that defines the construct.

Predictive validity

Using a measure to predict some future behavior

Concurrent validity

Research that examines the relationship between the measure and a criterion behavior at the same time. (Concurrent)

Convergent validity

Which scores on the measure in question are related to scores on other measures of the same or similar constructs. (Convergent) 

Discriminant validity

Measure is not related to variables with which is should not be related

Reactivity

Awareness of being measured changes an individuals behavior.

Nominal scale

Categories or groups simply differ from one another (No nominal variables)

Ordinal scales

Allow us to rank order the levels of the variable being studied.

Interval scale

Difference between the numbers on the scale is meaningful

Ratio Scales

Do have an absolute zero point that indicates the absence of the variables being measured.

Naturalistic Observation

researcher makes observations of individuals in their natural environment

Participant observation

researcher may be able to experience events in the same way as natural participants

Systematic observation

Careful observation of one or more specific behaviors in a particular setting

Reactivity

Possibility that the presence of the observer will affect peoples behaviors

Experience sampling method

Alert participants to complete a data collection procedure at that moment in time

Day reconstruction method

Asks participants to think about the previous day and write about distant episodes that occurred.

Psychobiography

Researcher applies psychological theory to explain the life of an individual

Archival Research

Using previously compiled information to answer research questions

Content analysis

Systematic analysis of existing documents

Response set

Tendency to respond to all questions from a particular perspective rather than to provide answers that are directly related to the questions

Social Desirability

Leads individuals to answer in the most socially acceptable way

Yea-saying

Tendency to agree constantly

Nah-saying

Tendency to disagree consistently

Closed-ended questions

A limited number of response alternatives are given

Open-ended

Respondents are free to answer in any way they likes

Rating Scales

People to provide “how much” judgements on any number of dimensions

Graphic rating scale

Requires a mark along a continuous 100-milimeter line that is anchored with descriptions at each end.

Semantic Differential scale

Respondents are asked to rate any concept using a 7-point scale

Response rate

Percentage of people who are asked to complete a survey who actually complete a survey

Interviewer bias

The fact that the interviewer is a unique human being interactive with another human being

Focus groups

Interview with a group of about 6-10 individuals brought together for a period of usually 2-3 hours

Panel Study

Same people are surveyed at two or more points in time

Sample

Participants from a population of interest

Population

All individuals of interest to the researcher

Probability samplling

Each member of the population has a specifiable probability of being chosen

Nonprobability sampling

The probability of any particular member of the population being chosen is unknown

Simple random sampling

Population is divided into subgroups; random sampling is used to select sample members from each subgroup

Cluster sampling

Researcher can identify ‘clusters’ of individuals and then sample from these clusters.

Purposive sampling 

Non-probability sampling procedure in which the researcher makes judgement regarding an individual for the sample

Snowball Sampling

Nonprobability sampling procedure in which one or more current research participants recruit others to become part of the sample

Quota Sampling

Chooses a sample that reflects a numerical composition of various subgroups in the population