|PSY 101 Research Enterprise in Psychology I|
Questions I asked in the 1st Week of Class:
- #1 Do lie detectors work, that is, can we figure out who is lying and who isn't with a polygraph ("lie detector")?
- #2 Does the full moon cause people to do strange and abnormal things?
- #3 Does listening to Mozart music make infants smarter?
- #4 Do people with opposite personalities attract each other?
As you should recall, the answer to all of these questions is FALSE
How would you research any of these questions?
What would you need to do to answer these questions?
Goals of science are "description, prediction, and control":
1 Measurement & Description (good but not yet enough)
- What the phenomenon does, looks like, etc.
- How much of the phenomenon exists (how heavy, tall, fast, hard, etc.)
2. Prediction & Understanding = Lawfulness
- Hypotheses: A tentative statement about the relationship between two variables
- Note that the concept of "hypothesis" in science is not the same as the concept of "theory" (see below)
- In a hypothesis, we predict that there IS a relationship
- Variables: any measurable conditions, events, characteristics, or behaviors that are examined or controlled in a research study
3. Control & Application of Laws (Doing something with the laws)
- Scientists hope ultimately to use the laws they discover to help human beings lead better lives
- Thus, there are always moral issues involved in science
Theory in science ≠ "theory" in ordinary language
- In ordinary language, theory means a kind of "educated guess"
- In science, theory means a well-tested explanation which successfully predicts the phenomenon under review. It can be defined as a "system of interrelated ideas used to explain a set of observations"
- the theory of aerodynamics explains why planes fly
- the theory of "germs" in medicine explains bacterial infections
Testability in Science
- Any scientific law must be "testable" or it is not scientific
- Science is NOT "proving something is true"
- Rather, science is being able to falsify a theory ("proving something is wrong")
- All scientific statements have to be willing to be found to be wrong (that is, falsified) or they are not scientific
- General theories (evolution, modern physics, etc.) cannot usually be tested as a whole. But different parts of the theory can be tested in many different ways. Any failure of a predicted part of the theory calls the whole theory into question.
Steps in a Scientific Investigation
1. Formulate a Testable Hypothesis (that is, some reality we claim is true)
Question: Are science faculty
subconsciously biased against women?
Hypothesis: Science faculty members ARE subconsciously biased against women.
What could we hypothesize? (and operationally define?)
- Who is a science faculty member?
- What do we mean by bias?
An operational definition describes precisely how to measure or identify the variable under review. Here are examples of operational definitions:
- Depression is equal to the number of symptoms on a depression measurement scale
- Self esteem is equal to the number of positive statements about one's self that a person endorses
- Likability is equal to the average of ratings from 1 ("utterly hateful") to 7 ("completely likable") that a target group gives to someone on a survey scale
- Accuracy is equal to the number of correct responses to some sort of task
- Processing speed is equal to the number of seconds of time that it takes someone to complete a task.
2. Select the Research Method & Design the Study
Researchers have to think of how they are going to carry out the study & test their hypotheses. Some of the options to consider would be
Participants (subjects) = the persons or animals whose behavior is systematically observed in a study
- Experiment? Manipulate some variable under controlled condition(s) and observe changes as a result
- Case Study? Focus upon the experience of one or a few subjects/participants
- Naturalistic Observation? Take careful measurements without intruding yourself in a real-world setting
- Survey? Provide participants with a written set of questions or interview the participants yourself
3. Collect the Data
Get the information which our research study design requires
- Direct Observation
- Questionnaire (Survey)
- Psychological Test
- Physiological Recording
- Examining Archival Records
4. Analyze the Data & Draw Conclusions
- Statistics analyze numbers: how much of a difference has to be there for it to be a real difference?
- Qualitative approaches analyze non-numerical data (e.g., themes, etc.)
5. Report the Findings
- Scientific journals, for example, in APA Journals
- Books, etc.
Advantages of a Scientific Approach to Research
- Clarity & precision (not vague or ambiguous)
- Intolerance of error
- Scientists are skeptical (even of their own ideas)
- If results of studies conflict, scientists want to know why
B. Looking for Causes: Experimental ResearchWhat is an experiment? A research approach in which the investigator controls the conditions under which research subjects or participants experience variables. In an experiment, the research subjects experience identical (or standard) conditions except for the variable under review.
Hypothesis: Science faculty members ARE subconsciously biased against women
Moss-Racusin et al. (2012)
A. Types of Variables
- Independent = Controlled by Investigator
- Dependent = Depends on what happens to the participant
- Independent => Identical application for a laboratory manager position except for name of applicant which is the independent variable (name = gender)
- Male name = John vs. Female name = Jennifer
- Dependent => Participants would read application and then rate the candidate on these dependent variables:
- Competence: How competent? (on a scale of 1 to 7)
- Hireability: How likely would you be to hire this applicant? (on a scale of 1 to 7)
- Mentoring: How willing would you be to mentor this applicant (on a scale of 1 to 5)
- Salary: What would you suggest be the starting salary (in a range between $15,000 and $50,000)
B. Types of Groups in an Experiment
- Experimental: those who are given the independent variable(s) to be tested
- Control: those who are not given the independent variable(s). They are treated in exactly the same way as the experimental group except for the independent variable.
In this science faculty member experiment, the control group might actually be considered those who received the male name, i.e., if we are looking if females are treated differently, the male name group would be the standard against which to judge. Thus, the experimental group would be those who got the female name, i.e., we want to see if they will rate the candidate differently than the control group.
- On each of these dependent variables, there is a significant difference between ratings given male vs. female applicants. Females are always rated below males. The hypothesis is supported.
- Female & male faculty raters did not differ in their overall pattern of ratings. Thus female faculty were equally likely to rate female-named applicants lower than male-named applicants.
C. Problems in an Experiment
- Extraneous variables: any variable that might influence the dependent variable but which is not being tested as the independent variable. You ultimately can't be sure what the independent variable really was.
- e.g., testing a group of children for motivation under different lighting conditions and all of the children are hungry
- e.g., measuring speed of processing information under different lighting conditions in an environment in which there is a lot of noise coming from the street
- Confounding variable: two variables are linked in some way that we cannot sort apart their effects
- e.g., testing a group of children for motivation and some children are hungry & some are well fed
- e.g., testing the verbal intelligence of a group of immigrants in which some know English & some do not know English
- Choosing an Experimental Group
- Need for Random Assignment to experimental vs. control group
- Random assignment assures that the two groups are essentially equal
D. Types of Design
- One (1) Independent Variable
- Two (2) Independent Variables
E. Advantages & Disadvantages of Experiments
- Advantage: Powerful: Cause & Effect can be isolated
- Disadvantage: Artificial
- Disadvantage: Some or even many variables can't be manipulated for practical or ethical reasons
Moss-Racusin, C. A., Dovidio, J. F., Brescoll, V. L, Graham, M. J., & Handelsman, J. (2012). Science faculty's subtle gender biases favor male students. Proceedings of the National Academic of Science (PNAS). Published online before print September 17, 2012. doi: 10.1073/pnas.1211286109 [link]