1. Research Methods
{ Quantitative, qualitative and critical thinking

2. Where to begin?

3. A hypothesis is an assumption made from
your own knowledge or common sense.
Hypothesis:
a proposed explanation to a phenomenon

6. Correlation refers to a relationship between two (or more)
variables in which they change together.
A positive correlation means that as one variable increases(e.g., ice
cream consumption) the other variable also increases (e.g., crime).
A negative correlation is just the opposite; as one variable increases
(e.g., socioeconomic status), the other variable decreases (e.g., infant
mortality rates).
What is correlation?

7. Yes…there is a correlation.

8. Causation refers to a relationship between two (or more) variables
where one variable causes the other. In order for a variable to cause
another, it must meet the following three criteria:
1. the variables must be correlated
2. one variable must precede the other variable in time
3. it must be shown that a different (third) variable is not causing
the change in the two variables of interest (a.k.a., spurious
correlation)
What is causality?

9. Correlation is not causation.

10. Spurious Correlation
Does it meet all three criteria?

11. 1. These variables are ones that are more or less
controlled.
2. Scientists manipulate these variables as they see fit.
3. They still vary, but the variation is relatively known
or taken into account.
4. Often there are many in a given study.
Independent Variables

12. 1. Dependent variables are not controlled or
manipulated in any way, but instead are simply
measured or registered.
2. These vary in relation to the independent variables,
and while results can be predicted, the data is
always measured.
3. There can be any number of dependent variables,
but usually there is one to isolate reason for variation.
Dependent Variables

13. Independent Dependent
(input) (output)
1. Intentionally manipulated 1. Intentionally left alone
2. Controlled 2. Measured
3. For example: known rate
Vary at 3. Vary at unknown rate
Cause
4. •If a scientist conducts an experiment to test the theory that a vitamin could
4. Effect
extend a person’s life-expectancy, then the independent variable is the
amount of vitamin that is given to the subjects within the experiment. This is
controlled by the experimenting scientist.
•The dependent variable, or the variable being affected by the independent
variable in this case, is life span.

14. Variables:
Type of School
Liberals Arts v. University
Type of Student
Athlete? Gender? GPA?
Time
Bedtime, Waking, Arrival
Mode of Transportation
Example: What affects a
student’s arrival to class?

15. http://www.wired.com/medtech/drugs/magazine/1
7-09/ff_placebo_effect?currentPage=all

16. Researchers beware!

17. Reliability and Validity
http://www.wadsworth.com/psychology_d/special_features/ext/workshops/reliability3.html

18. Reliability and Validity
http://www.wadsworth.com/psychology_d/special_features/ext/workshops/reliability3.html

19. Reliability and Validity

20. “do no harm,” informed consent, voluntary participation, and protected
populations.
Ethics

21. Science, junk science, pseudo-
science and non-science.
http://www.youtube.com/watch?v=8T_jwq9ph8k

22. Keeping it real.
http://www.ted.com/talks/ben_goldacre_battling_bad_science.html