Chapter 2: Research Methods
• There are 3 sets of interrelated goals:
1. Measurement and Description→developing measurement techniques that make it possible to
2. Understanding and Prediction→scientist believe that they understand events when they can explain
the reasons for the occurrence of the events. To evaluate their understanding, scientist make and
test their hypotheses.
3. Application and Control→once scientist understand a phenomenon, they can exert more control
• By integrating unrelated facts and principles into a coherent whole, theories permit psychologists to
make the leap from the description of behaviour to the understanding of behaviour.
• Scientiﬁc investigations are systematic, they follow an orderly pattern:
1. Step 1: Formulate a testable hypothesis→translate a theory into a testable hypothesis. To be
testable, scientiﬁc hypotheses must be formulated precisely, and the variables under study must be
clearly deﬁned. Researches achieve these clear formulations by providing operational
deﬁnitions(describe the actions or operations that will be used to measure or control a variable) of
the relevant variables.
2. Step 2: Select the Research Method and Design the Study→ﬁgure out how to put the hypothesis
to an empirical test. The research method depends on the nature of the question under study. The
various methods-experiments, case studies, surveys-each have advantages and disadvantages, so
the researcher has to consider them and select the strategy that is most appropriate. Once
researches have chosen a general method, they must take detailed plans for executing their study.
3. Step 3: Collect the Data→there are variety of data collection techniques, such as direct
observation, questionnaire, interview, psychological test, physiological recording, and examination
of archival records(see page 49).
4. Step 4: Analyze the Date and Draw Conclusions→the observations made in a study are usually
converted into numbers. Researchers use statistics to analyze their data. 5. Step 5: Report the Findings→scientiﬁc progress can only be achieved if the researches share their
ﬁndings with one another and with the general public. Researches prepare a report that is delivered
at a scientiﬁc meeting and submitted to a journal for publication.
• There are 2 advantages of the scientiﬁc approach. The ﬁrst is its clarity and precision, and the second
is its relative intolerance of error.
• The experiment is a research method in which the investigator manipulates a variable under carefully
controlled conditions and observes whether any changes occur in a second variable as a result. The
experiment allows researchers to detect cause-and-effect relationship, so psychologist depend on
this method more than any other.
• Random Assignment: ensures that every participant has an equal chance of being assigned to any of
• What are the differences between independent and dependent variables?
• The experimental group consists of the subjects who receive some special treatment in regard to the
independent variable. The control group consists of similar subjects who do not receiv