Week 6, Sampling.
Lecture notes
This week we will finish with basic experimental design, and discuss sampling.
Key issues in gathering a research sample:
Who do you want to generalize to?- Who is the target population?
- broad
increases
external validity - Narrow increases internal validity
- broad
- How do you decide who is a member?
- demographic / behavioral criteria?
- subjective / attitudinal
- What do you know about the population already – what is the “sampling frame”.
- Is the population “Hidden” in some way?
- Socially undesirable research topic?
- Easily available via telephone, door-to-door?
- Targeted / multi-frame; sampling every niche of a population
- Respondent driven or “snowball”; sampling entire social networks (click image for interesting paper on romantic linkages among youth).
- quota sampling.
Lecture notes are here.
Readings
Chapters 7 & 10.
Readinngs: An article from the New York Times on the importance of context in interpreting results from large studies of mothers who work. A Tribune piece on Sampling, statistics, and interpreting school test scores. Finally, the image to the right shows the extensive screening that takes place for a drug trial of anti-depressants. Click for a journal article that asks whether participants in drug studies of anti-depressants are representative of depressed patients generally. The article can be a bit technical, but I will use it in lecture
Discussion group Assignment
(Click for a Word copy of Week 6 assignment).
Rewrite your paper topic.
Take your discussion from last week or any direct feedback you have gotten and rewrite your paper topic. Try to make your current topic more clear or specific rather than starting from scratch, but feel free to change completely if you decide to.
Again, look at the paper assignment to see what your term paper will consist of. To get comfortable reading journal articles go to Guide to Psychology Articles.
Phenomenon: What is the larger question? What are you interested in explaining?
Theory: How does it work? What causes what? Why or how does it happen?
Be clearer about your Hypothetical Constructs and how they relate to one another. Now that you got some basic thoughts down from last week, try to hone these into more specific concepts. Frame these in “cause and effect” -type language to address how or why your phenomenon works.
Remember - your Introductory text book is a great place to find overviews of (and references to) general psychological theories.
Hypothesis: What is your specific prediction?
Make a prediction about specific variables that can be operationally defined, and that reflect the hypothetical constructs underlying your theory. The most common problem students have at this point is not being specific or concrete enough in their hypothesis.
- The variables must be concrete enough that you can describe specific operations that you will use to create or measure each variable
- It must clearly express the larger hypothetical constructs you are studying.
You can be proposing either a true experiment – where you control the Independent Variable and you randomly assign people to experimental v. control groups – or a quasi-experiment where you do not control the IV or you use existing groups.
We will return to these questions for your assignment in Week 8, where you will begin a first draft of your term paper.
