Single Subject (small n) Problems with group analysis Individual differences are ignored These are important factors! This logic is based on farming analysis! The logic of single subject is high levels of internal validity (control) then replication. Systematic, Direct
Experimental Single Subject Design Using a subject as their own control If we establish a pattern of responding and then change that pattern of responding at the exact moment the IV is present we conclude that it was the IV that had the effect
Reversal design Shifting conditions – must be something that is not a permanent change Baseline (Stability) Treatment (stability) Baseline (stability) Treatment (stability) ABA designs, ABAB designs, ABAC Showing effects across people Ethics
Multiple Baseline Several individuals Baselines overlap to control for environmental variables. The treatment is then introduced at different times for each If the behavior changes in each person at the treatment time, then the IV has the effect.
Changing criterion Modify the criteria as it is reached until a given level is desired Step down/up approach
Quasi Experimentation Internal vs. external validity Internal allows you to detect effects But is generally low in applicability External validity makes the study applicable But decreases chance to detect effect.
Archival studies Looking at events in history and measuring their effect Looking at records Looking at changes before and after. No ability to detect cause. Naturalistic observations combined with sound data collection.
Time series design Repeated measures Time one and time two are the minimum Can be an experimental treatment Pre M X post M Single group pre-post design. Remember – no control here – so cannot truly conclude if the X made the changes.
Interrupted time series Adding more pre and post tests Allows us to assess changes that we cant see with a single shot. M M M M X M M M M M
Multiple time series Just like multiple but uses a control group! No random assignment though. Adds some control – but still cant detect cause
Non-equiv before after design When your groups are different before the study starts. Or you expect they are! M X M M M Compare differences in terms of groups to themselves.
Ex-post facto design Retrospective comparisons An early event – with a later event Participating in debate – becoming a leader Medical or behavior problems associated with later issues (heart disease) Identify group of interest (those serial killers) Look for patters using various predictors Compare to a selected control group Could be randomly chosen people from the year book
Correlational designs Designs that are relating variables But not seeking to see which causes the other Used not to establish cause But to show a relationship to then allow for further study Prevents us from wasting time and resources
Naturalistic study Simply observing and describing Darwin on the HMS Beagle Started as simple observations Went on to develop ideas Eventually a theory Now tests of that theory Now it exists as a definition of life. Hawthorne effect (reactance) Being observed causes changes Use unobtrustive observations Selective perception We choose to focus on certain things We are influenced by what we expect to see Boredom – leads you to looking for boredom!