Psychology: Unit 2-Research, Stats, Testing & Intelligence

Hindsight Bias: The tendency to believe, after learning the outcome, that you knew all along.

Overconfidence: We tend to think we know more than we do.

The Barnum Effect: It is the tendency for people to accept very general or vague characterizations of themselves, and take them to be accurate.

Applied vs. Basic Research

Applied Research has clear, practical applications. "You can use it!!!"

Basic Research explores question that you may be curious about, but not intended to be immediately used. 

Hypothesis: Expresses a relationship between 2 variables.

• A variable is anything that can vary among participants in a  study. 

Independent Variable: Whatever is being manipulated in the experiment. (Usually a drug if it is involved) 

Dependent Variable: Whatever is being measured int the experiment. (Usually the effect of the drug if it is involved)

Operational Definition: Explains what you mean in your hypothesis.

• How will the variables be measured in "real life" terms. 

Types of Research

There are 3 types of research: descriptive, correlational, and experimental

Descriptive Research

• We describe what we see
• Any research that observes and records
• Types of Descriptive Research
• Case Studies: A detailed picture of one or a few subjects
• The Survey
• Most common type of study in psychology
• Measures correlation
• Cheap and fast
• use interview, mail, phone, internet, etc.
• Low response rate
• Naturalistic Observation

Random Sampling: Identify the population you want to study.

• The sample must be representative of the population you want to study.

Why do we sample?

• One reason is the False Consensus Effect, the tendency to overestimate the extent to which others share our beliefs and behaviors.

Survey Method: The Bad

•  Low Response Rate
• People Lie or just misinterpret themselves
• Wording Effects

Naturalistic Observation: Watch subjects in their naturalistic Environment

• Do not manipulate the environment

Hawthorne Effect: Just the fact that you know you are in an experiment can cause change

• Even the control group may experience change

Correlational Research

Correlational Method: Correlation expresses a relationship between 2 variables

• Does not show causation
• Measured using a correlation coefficient

o   A number that measures the strength of a relationship

o   Range is from -1 to +1

o   The relationship gets weaker the closer you get to zero

Here are some examples to try out. Which is a stronger correlation?

• -.13 or +.37
• -.72 or +.59

Types of Correlation

Positive Correlation: The variables go in the same direction

Negative Correlation: The variables go in the opposite direction.

Experimental Research: Explores cause and effect relationship

• Ex. Eating to many bananas causes constipation

Here is a small activity you can do to help you know the research methods better

• Choose what you believe to be the preferred method of study for each hypothesis below. If a problem can be studies using more than one approach, choose the method with the greater precision. Choose from the following:

N (Naturalistic Observation)         S (Survey)             C (Case Study)           E (Experimental Study)

1. Jogging increases lung capacity. ______
2. Individuals having one or more significant hobbies report more jobs satisfaction than individuals having no hobbies. _____
3. A person cannot learn language if they are not exposed to it in the first five years of life. _____
4. Unmarried cab drivers talk more with their customers than do married cab drivers. _____
5. The purchase of tranquilizers increases during monetary crisis. _____
6. Apes are capable of understanding language _____
7. More men than women report fantasies of making large sums of money. _____ 
8. Work productivity increases when workers are allowed flexible hours. _____

After you have completed the activity, check your answers.

1. E
2. S
3. C
4. N
5. N
6. C
7. S
8. E

Independent Variable (IV): The experimental factor that is being manipulated; the variable whose effect is being studied

Dependent Variable (DV): The variable that may change in response to manipulations of the IV; the variable that is being measured.

Experimental vs. Control Groups

Experimental Group: The condition of an experiment that exposes participants to the treatment.

• Receives the IV

Control Group: The condition of the experiment that serves as a comparison for evaluating the effect of the treatment

Types of Experimental Methods

Blind Study: Subjects are unaware if assigned to experimental or control groups

Double-Blind Study: Neither subjects nor experimenters know which group is control or experimental

Descriptive vs. Inferential Statistics

Descriptive Statistics: Describe the results of research

• Ex. 400 likely voters surveyed by phone on October 20. Of these, 230 said they will vote for Obama.

Inferential Statistics: Are used to make an inference or draw a conclusion beyond the raw data

• Ex. Obama will win the election

Measures of Central Tendency

Central Tendency: Where does the center of the data tend to be?

Mode: The most frequently occurring score in a distribution

• Ex. 2,2,2,5,5,6,7,7,7,7,7,9,10.

Mean: the arithmetic average of scores of distribution

• Add all the scores together, then divide the number of scores

Range: The difference between the highest and lowest scores in distribution.

Standard Deviation: A computed measure of how much scores vary around the mean.

• High standard deviation means scores are spread out
• Low standard deviation means scores are close together