1. Psychology 291 Lab 3 September 23 - 25, 2013
Hypotheses
Variables

2. Hypotheses Predictions Predicted relationship
(with or without direction)
Correlational
Predicted difference
Can be Causal

3. Variables Measured Independent Dependent
Variables that are assessed by the experimenter
Correlational vs. Differential studies
Quasi-Independent
A pre-existing characteristic that the experimenter uses to categorize the participants
e.g. Grouping Ps. according to sex
Independent
manipulated by the experimenter
e.g. Randomly assigning Ps. to receive placebo, low dose or high dose
Dependent
not under the control of the experimenter
the measured variable
e.g. Reaction time

4. Variables Cont.
Other variables outside the focus of the study that may affect the results
Extraneous
Unsystematic differences that affect the DV
Confounding
Variables that change systematically with IV

5. Confounding Variables
Extraneous Variables
Confounding Variables
- Affect any individual in any group
- Affect a group/condition within an experiment
X  Y
X  Individual Diff  Y
Confounding Variable
X acts on Individual differences leading to changes in Y
Changes in X lead to changes in Y, however a relationship between X & CV influence Y

6. What is “Love”? Psychological Feeling warm and fuzzy
Wanting to spend time with someone
Caring about someone
Showing interest in their interests
Physiological
Increased HR
Increased BP
Physical Arousal
Sweating
Behavioural
Holding hands
Kissing
Weighted glances

7. Operational Definition
Relates a concept to specific operations
Description of the procedures followed in order to manipulate, observe or measure a variable
Allows for knowing exactly what you are studying and directs how to study/measure it
All variables must have an operational definition

8. Summary Measured Variables Hypothesis: What is being predicted?
When trying to identify the hypothesis look for key words such as:
Hypothesized
Objective
Investigate
Measured Variables
Assessed by the experimenter
Pre-existing characteristic or measured
The independent variable is manipulated or if quasi-independent allows for categorization.
IV: What did the researchers change in order to group participants?
QV: What characteristic did researchers use to group the participants?
The dependent variable is what changed as a result of the manipulation.
What were researchers trying to find/elicit a change in?

9. A drug company is advertising a new drug that helps people recover from jet lag faster. You are skeptical, so you conduct an experiment to test their claim. In your experiment, 100 people are flown from San Francisco to Tokyo. During the flight, half of the participants are given the drug company’s new drug. The other half of the participants are given a placebo during the flight. Six hours after they land, all participants are asked to rate how sleepy and disoriented they feel.