Experimental Exam #2 Flashcards
Quasi Experiments
- Have an IV and a DV
- But cannot randomly assign participants to levels of the IV
- Loss of control over the experiment
Independent groups: non-equivalent control-groups design
Have a comparison group but no random assignment to a condition
Ex: Olympic medal level (gold, silver, bronze) and mental health
Repeated measures: interrupted time-series design
Participants/groups are measured multiple times before, during, and after an “interruption” (the event of interest)
Ex: COVID mask mandates
Combined: non-equivalent control-groups interrupted time-series design
combo of the two others
Validity and Quasi-experiments
1) Internal validity: you can not control for confounds → suffer a lot
2) Statistical validity: pretty good, same as experiments
3) Construct validity: can be really good; same as or even better than experiments
4) External validity: can be really good; same as or even better than experiments
Quasi experiments and causal claims
**It is very hard to make a causal claim with quasi-experiments: if there are several quasi-experiments that all have the same results, you can be more confident in making a casual claim
Survey research
Self-report data:
- Asking the person: the world’s best expert on the many aspects of life is probably you
- The most common type of data collected → may be overused
- May not be true for young children or older adults
Question Formats for self-report
1) Likert
2) Open-ended/free response
3) Forced choice items
4) Semantic differential items
Likert
Ex: rate your agreement with the following statement “I am creative”
- 1 = strongly disagree, 7 = strongly agree
Open-ended/free response
Ex: “do you think that you are creative”
Hard to do math on these kinds of questions → often have to go in and code words into numbers (how often did you use positive vs. negative words etc.)
Qualitative research → takes effort to make it quantitative
Forced choice items
Ex: have to pick one option (force into yes/no)
Pros: avoids fence sitting → have to make a decision
Cons: loses nuance (range of responses)
Semantic differential item
use opposite adjectives
Ex: rate your creativity:
1 = uncreative, 7 = creative
problems with questions
1) Leading questions
2) Limited range of response options
3) Double-barreled questions
4) Negatively-worded/confusingly worded questions
Leading questions
wording leads the participants to give the results you want
Limited range of response options
forcing people to say yes, no or I don’t know → there is a range of support and feelings within these (no room for nuance)
Double-barreled questions
touches on more than one issue but you can only give one answer
Response sets
1) Fence sitting (middle for every construct)
2) Acquiescence bias (yes saying)
3) Social desirability
Statistical analysis and response types
ANOVA: requires categorial IVs and continuous DVs
- Can NOT use a forced choice question as a DV and do an ANOVA
- Can use Likert item as a DV and do an ANOVA
Experiment and prioritized validity
Internal validity
frequency claim and prioritized validity
external validity
Association claim and prioritized validity
construct validity
bivariate correlation
how 2 variables (usually scale/continuous but not necessarily) are linearly related
- Has a standardized scale
- Coefifient “r”
Descriptive correlations
Descriptive: heres how two things trend together
**Effect size: quantifying the strength of the correlation
Inferential correlations
Inferential: can make a statement about a population
- To do this ask: is this correlation coefficient statistically different from a correlation of 0
- You can have weak but significant correlations (it mostly tells you if your N is large enough)
- If you have a huge N, everything is significant