I. METHODOLOGY
1. Definition - Methodology simply refers to the methods we use to conduct an investigation.
2. Systematic Research - Research in psychology is not haphazard. Following the basic principles of science there is some systematic way all research is conducted. Usually this means the psychologists approaches a problem from a theoretical perspective, they arrive at some question they want to answer which is called a hypothesis, and then perform a study to answer the question.
3. Naturalistic Observations - This is the simplest way we study behavior. You simply observe the behavior in its natural environment. This is frequently informal is usually the first step to allow you to get a better understanding of the behavior which allows further, more in-depth investigation.
4. Case Study - This is the gathering of detailed information on a specific individual. It is the technique used by Freud. It is difficult; however, to generalize past the person you are studying.
5. Surveys - Surveys ask a large number of people questions and are most frequently used to get an idea of the population’s attitudes toward something such as who they are going to vote for. They are only accurate, however, if the people surveys are representative of the population as a whole.
6. Correlations - This investigates the degree of relatedness between two variables. The range is from -1 to +1. A positive correlation indicates that a high score on one variable is associated with a high score on the other variable. For example, height and weight are positively correlated. As you get taller you tend to weigh more. A negative correlation means that a high score on one variable is associated with a low score on the other. For example, amount of brain damage and short-term memory. The more brain damage you have the poorer your short-term memory. Correlation does not imply causality. For example, there is a high correlation between umbrellas being open and the number of puddles on the ground. That does not mean the umbrellas cause puddles.
II. EXPERIMENTATION
1. Causation - If you want to determine if one variable causes another to happen you have to conduct an experiment. An experiment systematically alters one variable to see its effect on another variable.
2. Independent Variable - The variable that we alter systematically is referred to as the independent variable.
3. Dependent Variable - This is the outcome variable, the one we measure to see how it is affected by the independent variable.
4. Example - You are interested in seeing the immediate effects of watching TV violence on aggression. You show one group a violent film (Terminator II) and another group a nonviolent film (The Sound of Music). You then put each in a play situation and see how much pushing the child engages in. The IV is the film and the DV is the amount of pushing.
How Some Experiments Go Wrong
There are a number of events that can occur before, during and after an experiment that can have a negative impact on the psychological research study. Poorly planned studies will yield results that are useless, misleading or worse. Here are some of them.
1. Demand Characteristics: the participants will not behave normally during the experiment. Instead he or she will try to guess what the experimenter is trying to do or study and either "help" or "hinder" the researcher. For example, if a study is titled: "Weeping and Crying." the participants may get an idea about what the study is about and act accordingly.
2. Experimenter Bias. The researcher can have his or her own perception of each participant. If a researcher expects "smart" subjects to do well, those subjects generally end up doing better than other’s that were not expected to do well.
3. Dropout. The participants who decide to drop out of the study may be doing so because they possess certain characteristics that are not suited to the study.
To counter some of the problems involved, the primary investigator can design the study so that the experimenter and/or the participant are unaware of the purpose of the study. When just the participant or just the experimenter does not know the purpose, it is called a "single-blind" study. If both experimenter and participants do not know it is called "double-blind."
III. STATISTICS
1. Utility - We use statistics to determine the probability of differences in the DV are large enough so we are confident they are not due to chance. We can never be totally sure but we may be able to say we are 95% or 99% sure that differences are not due to chance.
2. Descriptive Statistics - These do not tell us anything about probability but only allow us to take a large amount of data and put it in some understandable form. These are grouped in two major forms: Measures of Central Tendency tell us about the center of our scores and Measures of Dispersion tell us how spread out our scores are.
3. Measures of Central Tendency - Mean is simple the average score. This is calculated by adding up all the scores and dividing by the total number of scores. The mode is the most frequently occurring score. The median is the middle most score.
4. Example - Scores on an exam. Ten people in the class.
| Scores | Statistics |
|
Total = 810 Mean = 81 Mode = 75 Median = 81 |
5. Measures of Dispersion - Range is the difference between the highest and lowest score. In this case 98 - 61 = 37. We usually use two other measures of dispersion: Variance which is the average squared distance between each score and the mean and Standard Deviation which is the average distance between each score and the mean.
6. Normal Curve - Decisions on probability are based on the normal curve (Draw on board). We assume that most behaviors and traits are distributed normally within the population. IQ is an example. The further you deviate from the middle, the more confident you are the person is abnormal.
7. Inferential Statistics - These are the tests we use to determine if groups differ significantly, that is, not by chance. In other words, we can infer a difference based on probability. Don't need to know any details.