[3-1] How do theories advance psychological science?
- Theories simplify and organize facts, and can offer a useful summary.
- Theories can bias our observations. They will be useful if it:
a) Organizes a range of self-reports and observations and
b) Implies predictions that anyone can use to check the theory or to derive practical
[3-2] How do psychologists use case studies, naturalistic observation, and surveys to observe
and describe behavior, and why is random sampling important?
- Case studies examine one individual in depth in the hope of revealing the truth. They show us
what can happen and often suggest directions for further study.
- Naturalistic observations describe behavior, not explain it. By observing actions, this paves
the way for further studies of thinking, language and emotion.
- Surveys look at many cases in less depth; asks people to report their behavior or opinions.
[3-3] What are positive and negative correlations, and why do they enable prediction but not
- A correlation is positive if two sets of scores, such as height and weight, tend to rise or fall
- A correlation is negative if two sets of scores relate inversely, one set is going up as the other
- Statistics can help is see what the naked eye sometimes misses; take relevant information
and chart it to see the type of correlation
- Correlations enable predictions because there are so many possible outcomes, yet we do not
know which variables are exactly the cause and effect. E.g. people have guns to cause murder
or murders cause people to have guns.
- Association DOES NOT prove causation. Correlation indicates the possibility of a cause-effect
relationship but does not prove such.
[3-4] What are the characteristics of experimentation that make it possible to isolate cause
- Experiments enable researchers to isolate the effects of one or more factors by:
a) Manipulating the factor(s) of interest and
b) Holding constant (“controlling”) other factors.
- An experiment manipulates a factor (independent variable) to determine its effect (measure
a dependent variable) and allow random assignment to control all other variables
[3-5] How can we describe data with measures of central tendency and variation?
- Organize data into a chart. E.g. bar graph
- Summarize the data using some measure of central tendency, a single score that represents a
whole set of scores; calculate the mean, median and mode
- The single number helps to know something about the amount of variation in the data- how
similar or diverse the scores are; calculate range and standard deviation
[3-6] How do we know whether an observed difference can be generalized to other
- Representative samples are better than biased samples
- Less-variable observations are more reliable than those that are more variable
- More cases are better than fewer; averages based on many cases are more reliable. E.g. when
comparing teachers at a school, observe many compared to only two
Theory- explains with principles that organize observations and predict behaviors or events. An
explanation using an integrated set of principles that organizes observations and predicts behaviors
or events. Hypothesis- A testable prediction, often implied by a theory.
Operational definition- a statement of the procedures (operations) used to define research
variables. E.g. Human intelligence may be operationally defined as “what an intelligence test
measures” and hunger may be “hours without eating.”
Replication- Repeating the essence of a research study, usually with differen