Sampling
Participants share similar key characteristics, such as age, gender, and motivation. What kind of sampling is this?
Matching pairs sampling
What challenges are created when using a pre-post study design?
Confounding issues arise; history and maturation bias are a concern; no ability to prove causation
Recruitment involved selecting fifty individuals aged 18-40 on a first-come, first-served basis. What does this mean for internal validity?
Self-selection bias is introduced, and there may not be equal demographics included e.g., more women than men. More motivated participants will self-select into the study.
A double-barreled question does what?
Asks about two distinct topics in one question.
Researchers use this experimental technique to combat order effects by varying the sequence in which participants experience different conditions.
Counterbalancing
Participants are asked to recruit future participants for a study. What kind of sampling is this?
Snowball sampling
A design that measures a single group of participants before and after an intervention but lacks a control group.
One-group pretest-posttest design
Time-based changes in participants—such as biological growth, aging, gains in knowledge, and cognitive development are what kind of threat to internal validity?
It is maturation bias, which may skew the results as the evaluator attributes the change in outcome to the program or intervention, when it might just be time.
A type of questionnaire item that sneaks in an assumption or pushes a respondent toward a predetermined answer
Leading question
This threat to internal validity occurs when the control group inadvertently receives the intervention meant only for the treatment group.
Contamination
What are the benefits of a random sample?
It addresses confounding, allows us to detect cause and effect relationships, and improves representativeness, and reduces selection bias.
What kind of design measures a dependent variable repeatedly before, during, and after a specific interruption or treatment event?
When a localized program runs alongside a sweeping national policy change, what internal validity threat are we facing?
Confounding, there is an information effect of the national change that we need to address.
Having participants take the same survey over time can introduce what kind of threat to internal validity?
Testing effect, they become comfortable or familiar with the survey and format.
Refers to the degree to which a study can confidently establish a causal relationship between an independent and dependent variable, free from confounding factors.
Internal validity
This purposive sampling technique deliberately selects outliers
Case deviant sampling
A research design enhances ethical viability by ensuring that the initial control or comparison group is not permanently denied the beneficial treatment.
Switching Replications Design
Participant loss over time in a longitudinal study can introduce bias if those who drop out differ systematically from those who remain. What is this called?
Attrition
When designing a Likert scale, these two golden rules ensure the options mirror each other on both sides and are evenly spaced.
Symmetry and balance
If Alexander Fleming had properly cleaned his laboratory dishes before going on vacation in 1928, penicillin as an antibiotic might never have been discovered. What is this called?
Counterfactual: it is what would have happened had the event/interruption/intervention/program not taken place.