Myers Module Three


Research Strategies

Psychological findings are based on the Scientific


But first, let's go back 700 years (or so) and learn about

Occam's Razor.

"when you have two competing theories that make exactly the same predictions, the simpler one is the better."

We always 'shave away' assumptions to get the simplest possible theory.

Research Strategies

Theory: An explanation using an integrated set of principles that organizes observations and events.


behaviors or

Hypothesis: A testable prediction often implied by the theory. A

null hypothesis

assumes that nothing is connected to anything. As such, it is


our natural tendency is to make connections.

Research Strategies

Operational definition: A statement of the procedures

(operations) used to define research variables. For example

human intelligence

may be operationally defined as ”what an intelligence test measures”.

Operational definitions allow us to make concrete decisions about research; we look for mistakes in logic here first. For example,

human intelligence

might include sociability, which a math skills test won't detect.

Research Strategies

Replication: Repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances.

To create a sucessful replication, the researcher must defend any and every choice or technique that differs from the original research. And in the real world, that always happens.

Scientific Method

Theory: Sleep boosts memory

Hypothesis: When sleep is deprived, people remember less from the day before.

Research and observations: Give study material to people before (a) an ample night's sleep, (b) a shortened night's sleep.

Then test memory.

Memorize Figure 3.1 for the next exam (mp27; cp24fig


Naturalistic Observation

Unobtrusive observation

–no easy task–of parent-child interaction.

Systematic analysis of the recordings.

Jane Goodall (1998) ”Observations, made in the natural habitat, helped to show that the societies and behaviors of animals are far more complex than previously supposed.”(mp28, cp26)

The Survey

A survey looks at many cases, but with less depth; it requires that the respondents have verbal and writing skills.

Wording effects are a major problem; critical thinkers will reflect on how the phrasing of a question might effect people's expressed opinions.

Placement is also important; the crucial question you are trying to ask cannot be obtrusive, that is, at the beginning or ending of the survey, but rather in the middle.

Random Sampling

There is a tendency in our natures to ignore the sampling bias (who did we ask questions to, and why), to generalize from a few vivid but unrepresentative cases.

This is a feature of our neural systems; we remember the dangerous, the hot, the sexy, the weird. Boring old everyday facts get lost in the shuffle.


A measure of the extent to which two factors vary together, and thus how well one factor predicts the other.


Correlation does not yield Causation.

It is our natural tendency to believe that one thing causes the other. Always consider the opposite.

A correlation coefficient is the statistical relationship between the two factors.


Correlations can range from +1.00 to -1.00

+1.00 Scores of one factor increase in direct proportion to scores on another.

-1.00 Scores of one factor decrease in direct proportion to scores on another.

The null hypothesis assumes a correlation of zero.

Nothing is connected to anything else.

The farthest natural observation and surveys can takes us statistically is the correlation of one factor to another. To prove one factor causes another, we need experimentation.


A research method in which an investigator manipulates one or more independent variables (the ones that cause change) to observe the effect on some behaviour or mental process (the dependent variable).

Random assignment aims to control other relevant factors.


Experimental group is the group that is exposed to the treatment (the independent variable).

Control group is the group that is not exposed to the treatment; it contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment (the independent variable).


Double-blind procedure: both the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or the placebo. Commonly used in drugevaluation studies.

Placebo effect. Experimental results can be caused by expectation alone; any effect on behavior caused by the act of administering an inert substance.

Experimental Design

Let's actually do an experiment, then.

I would like to know if there is a difference in accuracy of the use of targeting controls after anaerobic (AnE) versus aerobic (AE) exercise.

This is an idea driving real research:

To do this, I will need a sample size of 20 participants, whom will be randomly assigned to AnE and AE

Experimental Design

If we do a demo in the Fitness Centre with this class, realworld problems known as subject variables emerge.

How many gamers in the experimental and control groups?

How many athletes in the experimental and control groups?

How long a space of time between the exercise and the targeting test?

All of these subject variable problems can be solved by the use of

random assignment

to experimental and control groups.

Comparing Research Methods

Memorize Table 3.3 (mp37, cp35 fig.1.3)for the next exam.

For example: what is the basic purpose of descriptive research as compared to correlational research?

For example: what is the basic purpose of correlational research as compared to experimental research?

What is the weakness of the experimental method in psychology? Does this explain why the entire field has been rebuilt on the basis of neuroscience?

Basic Statistics

It is important to understand measures of central tendency.

Mode: the most frequently occurring score.

Mean: the arithmetical average of all scores.

Median: the midpoint score. If one arranges all the scores in order from the highest to the lowest, half will be above the median, and half below it.

Memorize Figure 3.8: The normal curve (mp40; cp38 fig.1.8)