Module 2

Module 2: Psychology and Science

3 main modes of research in psychology: Survey, Case study & Experimentation

1. SURVEYS -- asking a group of people to report behavior, experiences, opinions, etc. Also used for politics, marketing, TV, etc.

Advantage: A fast, easy way of getting information on tendencies within groups

Disadvantage: Bias and distortions can easily enter in. Common sources:

-- Wording of questions,

-- Desire to give nice rather than honest answers,

-- Characteristics of the questioner (e.g., gender, race, appearance of the questioner).

<note: these problems & solutions aren’t in your book under surveys, but some of the ideas are under “experimentation“>

Problem: To say something about a POPULATION, but it's usually impractical to ask every person in a population.

Solution: Ask a SAMPLE, a subset of that population, and extent our results to the population.

Problem: How do we get a REPRESENTATIVE SAMPLE -- a sample that accurately reflects the larger population? Whom do we ask?

Solution: By employing RANDOM SELECTION, where every person in the population has an equal chance of being selected for the sample.

General rule: A larger sample is more convincing than a smaller one because having a larger sample lessens the effect of atypical examples.

However: A large sample size cannot compensate for not having a representative sample. Generally, we want the largest representative sample possible.

2. CASE STUDY -- an in-depth analysis of the thoughts, feelings, beliefs, or behaviors of a single person.

Advantage: Provides information when finding a group of individuals is difficult (e.g. "Rainman")

Disadvantage: Distortion can be introduced by basing conclusions on someone who is atypical with respect to the phenomenon in question.

Other possible sources of error:

Personal beliefs can easily predispose us to seeing the world how we want (or expect) it to be -- rather than how it is.

-- It’s usually much easier to see what confirms our beliefs rather than what tells us our beliefs are wrong.

SELF-FULFILLING PROPHECIES: How one’s beliefs can easily lead to inadvertent behavior that brings about a confirmation of one’s beliefs.

-- e.g., if you believe and act as though the world is basically lousy, the world probably will treat you poorly -- which confirms the “prophecy.“

Note that psychology defines itself as a science largely to get around these sorts of common sources of error <not in book>

More common ideas & terms in psychological research:

PLACEBO: An inert stimulus that looks/sounds/tastes, etc. like an effective one (usually the one that’s being tested). E.g., an inert pill instead of one with a drug.

-- often used to confirm the effect of a treatment by comparing it to the absence of treatment.

PLACEBO EFFECT: People often experience an effect of a pretend treatment, even when there’s no actual treatment there.

-- examples: “Medicines” such as rhino horn, bear gallbladders, etc.

CORRELATION: A mathematical measure of the degree of relation between 2 phenomena -- the extent to which they predict one another.

The degree of correlation between 2 phenomena is indicated numerically by "r," which is known as a CORRELATION COEFFICIENT.

-1.0 <= r <= 1.0 (r ranges in value from -1 to 1, inclusively), and

Degree of relation a |r|

in graphic terms, r is a measure of the degree to which the plotted points on a scatterplot form a straight line.

the sign of r simply indicates the sign of the slope of the best-fit curve (i.e., the sign of m, where y = mx + b) -- hence the sign of r indicates either a direct (r > 0) or inverse (r < 0) relation between the 2 phenomena.

so...

r close to +1 (e.g., 0.92): strong correlation and a direct relation.

r close to -1 (e.g., -0.92): strong correlation and an inverse relation.

r close to 0 and + (e.g., 0.08): weak correlation and a direct relation.

r close to 0 and - (e.g., -0.08): weak correlation and an inverse relation.

Note that CORRELATION DOES NOT MEAN CAUSATION!

-- Just because there’s a strong correlation between 2 variables doesn’t necessarily mean that one is causing the other, since some third factor may be causing both (this is important).

2 basic settings where research happens

A. NATURALISTIC SETTING -- where behavior occurs in the same environment where it naturally happens.

-- This could be out in the wild, like Jane Goodall -- but it can also be in a classroom, on a city street -- wherever.

-- Problem: Effect of the presence of the observer <not in book>.

-- Problem: Complex environments make it hard to ascertain principles and causal relationships.

B. LABORATORY SETTING -- a simplified, controlled environment whose purpose is to filter out extraneous factors.

-- Problem: Does laboratory setting transfer to the real world?

3. EXPERIMENTATION -- used to establish causal relations, i.e., to answer the question, "WHY?"

Generally, experimental research is conducted by manipulating one factor (called the INDEPENDENT VARIABLE) while keeping all other factors constant -- to see if that factor produces the effect (called the DEPENDENT VARIABLE).

Also, experimental research involves looking at not just one group, but TWO. This is done to filter out unwanted effects of the experimental situation on the observations, so that what we observe is solely the product of the independent variable.

The EXPERIMENTAL GROUP -- has all of the particulars of the experimental situation, INCLUDING the presence of the independent variable.

The CONTROL GROUP -- has all of the particulars of the experimental situation, EXCEPT for the presence of the independent variable.

In both of these conditions or groups, we're looking for the dependent variable. If we observe the dependent variable in the experimental condition, but NOT in the control condition, then we can assert that the independent variable is the CAUSE of the dependent variable.

Possible problems:

Problem: Bias can creep in if we don‘t choose subjects who represent the population, or if we don’t assign subjects to the two groups in a way that reflects reality.

Solution: As we saw in survey, RANDOM SELECTION is used to select subjects within a population, and assignment of the subjects to the 2 groups is also done RANDOMLY.

Some other terms frequently used in psychological experimental research:

DOUBLE BLIND STUDY: an experiment where neither the subjects nor the assistants who deal directly with the subjects know which subjects are actually getting the independent variable. This is done because the assistants can easily and unwittingly affect the outcome if they do know.

Also, REPLICATION of scientific observations is important -- to increase our confidence in our earlier observations

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