What Is Scientific Inquiry?
In understanding behavior, psychological science has four goals: description, prediction, causal control, and explanation. As scientists, we must ask empirical questions if we are to achieve these goals. Science begins with a theory that represents our best guess for how and why something occurs. Theories give rise to hypotheses, specific predictions about what should occur if the theory is correct. It is the hypotheses, generated by theories, that psychological research sets out to test.

What Are the Type of Studies in Psychological Research?
There are three types of studies or research designs that can be used by the psychological researcher: experiments, correlational designs, and descriptive studies. It is important to be clear on what can and cannot be concluded from these different research designs. Experimentation is the only design that allows researchers to determine cause-and effect-relations. This is because the experimenter manipulates the independent variable while controlling other variables that might effect the outcome measure, also known as the dependent variable. Correlational designs allow us to identify relations between variables, but they do not allow us to determine causation. Correlation is not causation because the observation that two variables vary together does not provide information about the direction of the relationship between the variables, nor does it rule out the possibility that some third variable is responsible for the changes in the two correlated variables. The last type of research design covered is descriptive, or observational, studies in which the goal is simply to describe the behavior. This observation can be done from a distance, as in naturalistic observation, or the observations can be made while participating in the behavior being studied.

Memorizing the numerous structures in the brain can be a daunting task. Being able to visualize where in the brain these structures are located will help your study of this material. In learning the function of these brain structures, think about what sort of impairments would result from damage to the various structures.

What Are the Data Collection Methods of Psychological Science?
The text outlines four basic methods for collecting data; you should be able to name examples of each of these and describe the relative benefits and limitations of each method in specific detail:

With all research designs, there are several ethical issues that must be considered, including issues of confidentiality and informed consent. You should be familiar with these issues—not just because you are reading this chapter but in the event that you someday participate in psychological research. Finally, the researchers also need to be aware of how their expectations and biases may subtly influence the way that they code behavior and affect how they interact with their research participants.

How Are Data Analyzed and Evaluated? If the data that a researcher has collected are going to be of any use in testing a hypothesis, they must be valid (related to the question being studied), they must be reliable (consistent or stable), and they must be accurate (free from error). Descriptive statistics allow the researcher to summarize the data that have been collected. Measures of central tendency allow us to summarize the data into a single value. There are three measures of central tendency. The first is the mean, or the average of all of the scores. Sometimes a collection of data will have several extreme scores that will make the mean an inappropriate measure, in that case, the median, or middle score in the distribution, is a better measure of central tendency. The last measure of central tendency is the mode, or most common score in the collection of data. The mode is an appropriate measure when you have categorical data that cannot be averaged, such as gender or a diagnosis.

The next important piece of information to know about a collection of data is how the data vary around that measure of central tendency, and the standard deviation is the most commonly used measure of variability. Another descriptive statistic discussed in this chapter is the correlation coefficient, which describes the how two variables vary together. Correlations range from –1.00 to +1.00. The absolute value of the correlation describes the strength of the relationship, where 0 is no relationship, 1.00 is a perfect relationship, and the sign of the correlation indicates the nature of the relationship. A positive correlation means that as one variable increases the other variable also increases, and a negative correlation indicates that as one increases, the other decreases. Finally, in this section, the authors touch on inferential statistics. Inferential statistics enable a researcher to determine the likelihood that differences observed in a study occurred by chance. If the probability of such a chance difference is low, then the results are considered statistically significant.