Term
| Why are the answers that flow from the scientific approach more reliable than those based on intuition and common sense? |
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Definition
| Although common sense often serves us well, we are prone to hindsight bias (also called the “I-knew-it-all-along phenomenon”), the tendency to believe, after learning an outcome, that we would have foreseen it. We also are routinely overconfident of our judgments, thanks partly to our bias to seek information that confirms them. Although limited by the testable questions it can address, scientific inquiry can help us sift reality from illusion and restrain the biases of our unaided intuition. |
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Term
| What are three main components of the scientific attitude? |
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Definition
| The three components of the scientific attitude are (1) a curious eagerness to (2) skeptically scrutinize competing ideas and (3) an open-minded humility before nature. This attitude carries into everyday life as critical thinking, which examines assumptions, discerns hidden values, evaluates evidence, and assesses outcomes. Putting ideas, even crazy-sounding ideas, to the test helps us winnow sense from nonsense. |
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Term
| How do theories advance psychological science? |
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Definition
| Psychological theories organize observations and imply predictive hypotheses. After constructing precise operational definitions of their procedures, researchers test their hypotheses, validate and refine the theory, and, sometimes, suggest practical applications. If other researchers can replicate the study with similar results, we can then place greater confidence in the conclusion. |
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Term
| What are positive and negative correlations, and why do they enable prediction but not cause-effect explanation? |
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Definition
| Scatterplots help us to see correlations. A positive correlation (ranging from 0 to +1.00) indicates the extent to which two factors rise together. In a negative correlation (ranging from 0 to –1.00), one item rises as the other falls. An association (sometimes stated as a correlation coefficient) indicates the possibility of a cause-effect relationship, but it does not prove the direction of the influence, or whether an underlying third factor may explain the correlation. |
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Term
| What are illusory correlations? |
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Definition
| Illusory correlations are random events that we notice and falsely assume are related. Patterns or sequences occur naturally in sets of random data, but we tend to interpret these patterns as meaningful connections, perhaps in an attempt to make sense of the world around us. |
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Term
| How do experiments, powered by random assignment, clarify cause and effect? |
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Definition
| To discover cause-effect relationships, psychologists conduct experiments, manipulating one or more factors of interest and controlling other factors. Random assignment minimizes preexisting differences between the experimental group (exposed to the treatment) and the control group (given a placebo or different version of the treatment). The independent variable is the factor you manipulate to study its effect. The dependent variable is the factor you measure to discover any changes that occur in response to these manipulations. Studies may use a double-blind procedure to avoid the placebo effect and researcher’s bias |
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Term
| How can we describe data with measures of central tendency and variation? |
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Definition
| Three measures of central tendency are the median (the middle score in a group of data), the mode (the most frequently occurring score), and the mean (the arithmetic average). Measures of variation tell us how similar or diverse data are. A range describes the gap between the highest and lowest scores. The more useful measure, the standard deviation, states how much scores vary around the mean, or average, score. The normal curve is a bell-shaped curve that describes the distribution of many types of data. |
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Term
| What principles can guide our making generalizations from samples and deciding whether differences are significant? |
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Definition
Three principles are worth remembering: (1) Representative samples are better than biased samples. (2) Less-variable observations are more reliable than those that are more variable. (3) More cases are better than fewer.
When averages from two samples are each reliable measures of their own populations, and the difference between them is relatively large, we can assume that the result is statistically significant—that it did not occur by chance alone. |
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Term
| Can laboratory experiments illuminate everyday life? |
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Definition
| By intentionally creating a controlled, artificial environment in the lab, researchers aim to test theoretical principles. These general principles help explain everyday behaviors. |
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Term
| Does behavior depend on one’s culture and gender? |
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Definition
| Attitudes and behaviors vary across cultures, but the underlying principles vary much less because of our human kinship. Although gender differences tend to capture attention, it is important to remember our greater gender similarities. |
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Term
| Why do psychologists study animals, and is it ethical to experiment on animals? |
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Definition
| Some psychologists are primarily interested in animal behavior. Others study animals to better understand the physiological and psychological processes shared by humans. Under ethical and legal guidelines animals used in experiments rarely experience pain. Nevertheless, animal rights groups raise an important issue: Even if it leads to the relief of human suffering, is an animal’s temporary suffering justified? |
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Term
| Is it ethical to experiment on people? |
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Definition
| Researchers may temporarily stress or deceive people in order to learn something important. Professional ethical standards provide guidelines concerning the treatment of both human and animal participants. |
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Term
| Is psychology free of value judgments? |
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Definition
| Psychologists’ values influence their choice of research topics, their theories and observations, their labels for behavior, and their professional advice. Applications of psychology’s principles have been used mainly in the service of humanity. |
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Term
| How do psychologists observe and describe behavior? |
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Definition
| Psychologists observe and describe behavior using individual case studies, surveys among random samples of a population, and naturalistic observations. In generalizing from observations, remember: Representative samples are a better guide than vivid anecdotes. |
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Term
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Definition
| the tendency to believe, after learning an outcome, that one would have foreseen it. (Also known as the I-knew-it-all-along phenomenon.) |
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Term
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Definition
| thinking that does not blindly accept arguments and conclusions. Rather, it examines assumptions, discerns hidden values, evaluates evidence, and assesses conclusions |
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Term
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Definition
| an explanation using an integrated set of principles that organizes observations and predicts behaviors or events |
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Term
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Definition
| a testable prediction, often implied by a theory. |
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Term
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Definition
| a statement of the procedures (operations) used to define research variables. For example, human intelligence may be operationally defined as what an intelligence test measures. |
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Term
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Definition
| repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances. |
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Term
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Definition
| an observation technique in which one person is studied in depth in the hope of revealing universal principles. |
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Term
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Definition
| a technique for ascertaining the self-reported attitudes or behaviors of a particular group, usually by questioning a representative, random sample of the group. |
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Term
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Definition
| all the cases in a group being studied, from which samples may be drawn. (Note: Except for national studies, this does not refer to a country’s whole population.) |
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Term
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Definition
| a sample that fairly represents a population because each member has an equal chance of inclusion. |
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Term
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Definition
| observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation. |
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Term
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Definition
| a measure of the extent to which two factors vary together, and thus of how well either factor predicts the other. |
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Term
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Definition
| a statistical index of the relationship between two things (from −1 to +1). |
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Term
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Definition
| a graphed cluster of dots, each of which represents the values of two variables. The slope of the points suggests the direction of the relationship between the two variables. The amount of scatter suggests the strength of the correlation (little scatter indicates high correlation). |
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Term
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Definition
| the perception of a relationship where none exists. |
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Term
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Definition
| a research method in which an investigator manipulates one or more factors (independent variables) to observe the effect on some behavior or mental process (the dependent variable). By random assignment of participants, the experimenter aims to control other relevant factors. |
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Term
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Definition
| assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between those assigned to the different groups. |
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Term
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Definition
| an experimental procedure in which both the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo. Commonly used in drug-evaluation studies. |
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Term
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Definition
| in an experiment, the group that is exposed to the treatment, that is, to one version of the independent variable. |
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Term
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Definition
| in an experiment, the group that is not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment. |
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Term
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Definition
| the experimental factor that is manipulated; the variable whose effect is being studied. |
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Term
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Definition
| the outcome factor; the variable that may change in response to manipulations of the independent variable. |
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Term
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Definition
| the most frequently occurring score(s) in a distribution. |
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Term
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Definition
| the arithmetic average of a distribution, obtained by adding the scores and then dividing by the number of scores. |
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Term
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Definition
| the middle score in a distribution; half the scores are above it and half are below it. |
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Term
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Definition
| the difference between the highest and lowest scores in a distribution. |
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Term
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Definition
| a computed measure of how much scores vary around the mean score. |
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Term
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Definition
| (normal distribution) a symmetrical, bell-shaped curve that describes the distribution of many types of data; most scores fall near the mean, or average (68 percent fall within one standard deviation of it), and fewer and fewer near the extremes. |
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Term
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Definition
| a statistical statement of how likely it is that an obtained result occurred by chance. |
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Term
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Definition
| the enduring behaviors, ideas, attitudes, and traditions shared by a group of people and transmitted from one generation to the next. |
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