Key Concepts in Research Methods: Descriptive, Sampling, Validity, and Survey Techniques

Descriptive research

Research that describes characteristics of a population or phenomenon.

Observational method

Involves close observation and documentation of a behavior, good for natural settings, high external validity but low control/internal validity.

Case study

Detailed study of one individual or special population, captures unique individual cases but might not generalize, low external validity.

Survey

Collection of data by asking about actions, thoughts, ideas, beliefs through questionnaires or interviews.

Mistakes to avoid in surveys

Include asking questions that participants may not know the answer to or leading questions that could bias the answer.

Loaded question

Presumes something before the question that could bias the answer.

Compound questions

Questions that can have more than one answer and tap into different constructs.

Double negative

Confusing wording that is likely to be misinterpreted.

Self-report

A response set where participants answer questions in a systematic manner unrelated to their content.

Social desirability

The tendency to answer questions in a way that makes one look favorable.

Faking bad

Answering questions in a way that scores high or low on perceived negative traits.

Reliability for self-report

Can be calculated using test-retest, parallel forms, and split-half methods.

Inter-rater reliability

How much agreement there is among different raters.

Validity

The degree to which evidence supports conclusions or claims made about the data.

External validity

Degree to which results can be generalized beyond the current study to other people, situations, or time periods.

Sampling

The process of selecting a subset of a population for inclusion in an experiment.

Representative sampling

Uses random sampling where every member of the population has an equal chance of being chosen.

Simple random sample

A sample chosen randomly, possibly using a number generator.

Cluster sample

Randomly choosing within a cluster based on categorical variables.

Systematic random sampling

Selecting every nth person based on a rule.

Stratified random sampling

Sample chosen from distinct subgroups (strata) based on continuous variables.

Non-probability sampling

Does not use random sampling, leading to potential sample bias.

Convenience sampling

Sampling governed by who is readily available.

Judgmental sampling

Researcher selects participants based on preexisting knowledge or professional judgment.

Quota sampling

Sampling a preset number of people based on specific background characteristics.

Snowball sampling

Participants recruit additional participants.

Random sampling vs. Random assignment

Random sampling happens before the experiment and is important for external validity; random assignment occurs during the study and is important for internal validity.

Association Claims

Priorities include construct and statistical validity, focusing on how well variables are measured and the strength of the association.