Methods in Psychology PDF

Chapter 2 Methods in Psychology Copyright © 2023 by Macmillan Learning. All rights reserved PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Chapter Outline ▪ Empiricism:...

Chapter 2 Methods in Psychology Copyright © 2023 by Macmillan Learning. All rights reserved PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Chapter Outline ▪ Empiricism: How to Know Stuff ▪ Methods of Observation: Discovering What People Do ▪ Methods of Explanation: Discovering Why People Do What They Do Copyright © 2023 by Macmillan Learning. All rights reserved ▪ Thinking Critically About Evidence ▪ The Ethics of Science: Doing What’s Right PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Empiricism: How to Know Stuff ▪ Scientific method: Set of principles about the appropriate relationship between ideas using empirical evidence ▪ Empiricism: Belief that accurate knowledge can be acquired through observation; essential Copyright © 2023 by Macmillan Learning. All rights reserved element in scientific method ▪ Dogmatism: Description of Euclid and Ptolemy believed that our eyes the tendency to cling to work by emitting rays that go out and one’s beliefs “touch” the objects we see; al-Haytham (965-1039) disagreed. PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition The Scientific Method ▪ Scientific method: Procedure for using empirical evidence to establish facts ▪ Theory: Explanation of a natural phenomenon; can never be proved right Copyright © 2023 by Macmillan Learning. All rights reserved ▪ Hypothesis: Falsifiable prediction made by a theory PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition The Art of Looking ▪ Empirical method: Set of rules and techniques for observation ▪ People are difficult to study because of their complexity, variability, and reactivity. Copyright © 2023 by Macmillan Learning. All rights reserved ▪ Kinds of methods Frames 2 and 3 of this historic series ▪ Methods of observation of photos by Eadweard Muybridge ▪ Methods of explanation (1830–1904) PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition A World of Difference Are Heroes and Sheroes Divided by Zeroes? The history of science is replete with men. ▪ So where are all the women? ▪ Until recently, women’s educational and employment opportunities were limited. ▪ Men and women have different interests and talents. ▪ Men are often more interested in scientific topics. ▪ Women are more variable than men in quantitative Copyright © 2023 by Macmillan Learning. All rights reserved ability and visuo-spatial ability. Why do you think this occurs? Are these sex differences innate? How do you know? PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition The World’s First Scientist ▪ In 1834, William Whewell coined the word scientist to describe a remarkable astronomer, physicist, and chemist named Mary Somerville. Copyright © 2023 by Macmillan Learning. All rights reserved ▪ Few people remember that the world’s first scientist was a woman. PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Methods of Observation: Discovering What People Do ▪ Observe: Use of one’s senses to learn about the properties of an event or an object ▪ Limitations of everyday observation ▪ Inconsistent ▪ Incomplete ▪ Scientific techniques for overcoming these Copyright © 2023 by Macmillan Learning. All rights reserved limitations ▪ Measurement ▪ Description PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition What to Measure and How to Measure It ▪ Operational definition: Description of property in measurable terms ▪ Key feature of a good operational definition ▪ Construct validity: Extent to which the thing being measured adequately characterizes the property. ▪ Key features of a good detector ▪ Reliability: Tendency for a measure to produce the Copyright © 2023 by Macmillan Learning. All rights reserved same measurement whenever it is used to measure the same thing ▪ Power: Ability of a measure to detect conditions specified in the operational definition PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Measurement ▪ There are two steps in the measurement of a property. Copyright © 2023 by Macmillan Learning. All rights reserved PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Power and Reliability at the Olympics ▪ Usain Bolt ran the 100 metre race in 9.58 seconds, and Yohan Blake ran it Copyright © 2023 by Macmillan Learning. All rights reserved in 9.75 seconds. If judges did not have powerful speed-detectors, they might have mistakenly concluded that the two men were tied. ▪ Judges in the sport of ice dancing rate qualities of performance related to athleticism and artistry, and they are consistent (reliable) in their ratings. ▪ Tessa Virtue and Scott Moir, champion ice dancers, clearly measure up. PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Demand Characteristics: Doing What Is Expected (part 1) ▪ Demand characteristics: Aspects of an observational setting that cause people to behave as they think someone else wants or expects ▪ These characteristics make it hard to measure behaviour as it typically unfolds. Copyright © 2023 by Macmillan Learning. All rights reserved PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Demand Characteristics: Doing What Is Expected (part 2) ▪ Psychologists avoid demand characteristics by observing people without their knowledge. ▪ Naturalistic observation: Technique for gathering scientific information by unobtrusively observing people in their natural environments ▪ Naturalistic observation is not always practical. ▪ Some events are not naturally occurring. ▪ Some events can only be observed through direct Copyright © 2023 by Macmillan Learning. All rights reserved interaction. ▪ Observer bias may occur. PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition How Do Researchers Measure “Pace of Life’? Copyright © 2023 by Macmillan Learning. All rights reserved ▪ They make naturalistic observations—in this case, by measuring the average walking speed of pedestrians in different cities. PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Demand Characteristics: Doing What Is Expected (part 3) ▪ Techniques for avoiding demand characteristics ▪ Privacy ▪ Control ▪ Unawareness Copyright © 2023 by Macmillan Learning. All rights reserved PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Observer Bias: Seeing What Is Expected ▪ Observer bias: Tendency for observers’ expectations to influence what they believe they observed and what they actually observed. ▪ Why does this occur? ▪ Expectations can influence observations. ▪ Expectations can influence reality. Copyright © 2023 by Macmillan Learning. All rights reserved ▪ How can it be avoided? ▪ Double-blind study PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition An Example of Observer Bias ▪ Robert Parker is one of the world’s foremost wine critics. ▪ His ratings indicate how good a wine tastes—but can they also influence how good a wine tastes? Copyright © 2023 by Macmillan Learning. All rights reserved Would knowledge of his ratings affect participants’ ratings? Why? Why not? PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Description ▪ Population: Complete collection of people: rarely measured ▪ Sample: Partial collection of people drawn from a population ▪ Psychologists have two techniques for Copyright © 2023 by Macmillan Learning. All rights reserved analyzing data. ▪ Graphic representations ▪ Descriptive statistics PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Graphic Representations: Picturing the Measurements ▪ Graphic representations: Describe data in two ways ▪ Frequency distribution: Graphic representation showing the number of times in which the measurement of a property takes on each of its possible values Copyright © 2023 by Macmillan Learning. All rights reserved ▪ Normal distribution: Mathematically defined frequency distribution in which most measurements are concentrated around the middle PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Frequency Distributions ▪ What do these distributions reveal about reported level of happiness? Copyright © 2023 by Macmillan Learning. All rights reserved PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Descriptive Statistics: Summarizing the Data ▪ Descriptive statistics: Brief summary statements about essential information from a frequency distribution. ▪ Central tendency (centre or midpoint) Copyright © 2023 by Macmillan Learning. All rights reserved ▪ Mode ▪ Mean ▪ Median ▪ Skewed distribution PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Calculating Descriptive Statistics Copyright © 2023 by Macmillan Learning. All rights reserved PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Differently Shaped Distributions Copyright © 2023 by Macmillan Learning. All rights reserved PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Variability: How Wide Is the Distribution? ▪ Variability: Extent measurements differ; tell how much the measurements differ from each other or roughly how wide the distribution is ▪ Range: Value of the largest measurement in a frequency distribution minus the value of the smallest measurement Copyright © 2023 by Macmillan Learning. All rights reserved ▪ Standard deviation: Statistic that describes the average difference between the measurements in frequency distribution and the mean of that distribution PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Distributions Can Differ in Variability or Central Tendency Copyright © 2023 by Macmillan Learning. All rights reserved PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Methods of Explanation: Discovering Why People Do What They Do ▪ Correlation: Relationship between variables in which variations in the value of one variable are synchronized with variations in the value of the other ▪ Variable Property that can have more than one value Copyright © 2023 by Macmillan Learning. All rights reserved PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition  No. of Countries Hours of Named in One Participant Sleep Minute Hypothetical Data A 0 11 Showing the B 0 17 C 2.7 16 Relationship Between D 3.1 21 Sleep and Money E 4.4 17 F 5.5 16 G 7.6 31 Why are correlations H 7.9 41 the ultimate time I 8 40 J 8.1 35 Copyright © 2023 by Macmillan Learning. All rights reserved savers? K 8.6 38 L 9 43 PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Synchronized Patterns of Variation ▪ Synchronized patterns of variation ▪ Measure pair of variables ▪ Repeat; make a series of measurements ▪ Examine measurements and try to discern pattern ▪ When two variables are correlated, Copyright © 2023 by Macmillan Learning. All rights reserved knowledge of one variable value can be used to predict value of another variable ▪ Without having to measure it PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Measuring the Direction and Strength of a Correlation ▪ Correlation direction: Either positive or negative ▪ Positive correlation = more-is-more relationship ▪ Negative correlation = more-is-less relationship ▪ Correlation strength ▪ Limited range ▪ r ranges » –1.0 (perfect negative correlation) » +1.0 (perfect positive correlation) Copyright © 2023 by Macmillan Learning. All rights reserved » 0 (no correlation) ▪ Correlation coefficient: Measure of the direction and strength of a correlation (r) Let’s take a closer look! PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Graphing Correlations ▪ This is what three different kinds of correlations look like when graphed. Copyright © 2023 by Macmillan Learning. All rights reserved PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Positive Correlations of Different Strengths The diagonal lines on these three graphs show “the rule.” When the exceptions to the rule are few and small, then the positive correlation is strong, and r moves towards 1. But when the exceptions are many and large, the positive correlation is weak, and r moves towards 0. Copyright © 2023 by Macmillan Learning. All rights reserved PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Causation ▪ Sometimes we see causal relationships that do not exist. ▪ Natural correlations: Correlations observed in the world around us ▪ Third-variable problem (Z): Copyright © 2023 by Macmillan Learning. All rights reserved ▪ Natural correlation between two variables cannot be taken as evidence of a causal relationship between them because a third variable might be causing them both. PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Causes of Correlation Three possible reasons why X and Y are correlated: X → Y ,Y → X , or Z → X & Y. Copyright © 2023 by Macmillan Learning. All rights reserved PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Experimentation: Establishing Causation ▪ Experimentation ▪ Technique for establishing the causal relationship between variables ▪ Elimination of differences between Copyright © 2023 by Macmillan Learning. All rights reserved groups by examining two key features PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Three Steps of Experimentation (part 1) ▪ Experimentation allows establishment of causal relationship between variables by doing three things: ▪ Manipulate ▪ Manipulate independent variable; create at least two conditions. ▪ Independent variable: Variable that is manipulated in an experiment ▪ Measure Copyright © 2023 by Macmillan Learning. All rights reserved ▪ Measure dependent variable ▪ Dependent variable: Variable that is measured in an experiment ▪ Compare ▪ Compare measurements of conditions with each other. PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Three Steps of Experimentation (part 2) Copyright © 2023 by Macmillan Learning. All rights reserved PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Manipulation: Making Different Conditions ▪ Manipulation: Technique for determining the causal power of a variable by actively changing its value Copyright © 2023 by Macmillan Learning. All rights reserved PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Random Assignment Copyright © 2023 by Macmillan Learning. All rights reserved PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Hot Science Hate Posts and Hate Crimes: Not Just a Correlation Copyright © 2023 by Macmillan Learning. All rights reserved The number of hate crimes and hate posts in Germany from 2015 to 2017. PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Random Assignment: Making Sure Conditions Differ in Just One Way ▪ Random assignment: Procedure that lets chance assign participants to the experimental or control group ▪ Self-selection: Problem that occurs when anything about a participant determines Copyright © 2023 by Macmillan Learning. All rights reserved whether they will be included in the experimental or control group PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Statistical Testing: Making Sure Conditions Don’t Differ by Chance ▪ Calculating the odds that random assignment has failed each time experiment is conducted. ▪ Generally, not accepting experimental results unless the calculation suggests there is less than a 5% chance that those results would have occurred if random assignment had failed. ▪ Statistical significance ▪ Is determined when we calculate the odds that Copyright © 2023 by Macmillan Learning. All rights reserved random assignment has failed through inferential statistics ▪ Statistically significant results: p <.05 ▪ Failure of random assignment: p >.05 PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition The Real World: The Surprisingly High Likelihood of Unlikely Coincidences ▪ A recent survey found that roughly half of college graduates believe in extrasensory perception (ESP). ▪ By not using probability theory, people routinely underestimate the likelihood of coincidences. ▪ Mathematics professor John Paulos noted, “In reality, the most astonishingly incredible Copyright © 2023 by Macmillan Learning. All rights reserved coincidence imaginable would be the complete absence of all coincidence” (Neimark, 2004). What do you think? PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Drawing Conclusions ▪ Internal validity: Attribute of an experiment that allows it to establish causal relationships ▪ External validity: Attribute of an Copyright © 2023 by Macmillan Learning. All rights reserved Does piercing make a person more or experiment in which less attractive? On what does your variables have been answer depend? operationally defined in a representative way. PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition The Generalizability Restriction: “In the People We Studied...” ▪ Case method: Method of gathering scientific knowledge by studying a single individual ▪ Random sampling: Technique for choosing participants to ensure that every member of a population has an equal chance of being included in the sample ▪ Sample is representative of population. ▪ Generalization from sample to population can be made. ▪ Nonrandom sampling: Acceptable technique if the similarity Copyright © 2023 by Macmillan Learning. All rights reserved between a sample and the population doesn’t matter, when direct replication is available, and if the similarity between the two is a reasonable starting assumption PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Is Nonrandom Sampling a Fatal Flaw in Psychological Science? ▪ No, and there are two reasons why. ▪ First, sometimes the representativeness of a sample doesn’t matter. ▪ Second, sometimes the representativeness of the sample is a reasonable starting assumption. Copyright © 2023 by Macmillan Learning. All rights reserved ▪ Learning about some people does not necessarily tell us about all people, but it can still tell us a lot. PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition The Reliability Restriction: “It Is Likely That…” ▪ Replication: Experiment that uses the same procedures as a previous experiment but with a new sample from the same population ▪ Type I error: Error occurs when researchers conclude that there is a causal relationship between two variables when there is not. Copyright © 2023 by Macmillan Learning. All rights reserved ▪ Type II error: Error occurs when researchers conclude that there is not a causal relationship between two variables when, in fact, there is PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Other Voices Psychology Is Not in Crisis ▪ Is psychology amid a research crisis? ▪ Is failure to replicate a normal part of how science works? Why? Why not? ▪ Do failures to replicate mean that original experiments are worthless? Why? Why not? Copyright © 2023 by Macmillan Learning. All rights reserved (Hint: Context!) PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Thinking Critically About Evidence ▪ Critical thinking: Involves asking tough questions. ▪ Has evidence been interpreted in an unbiased way? ▪ Does the evidence tell Copyright © 2023 by Macmillan Learning. All rights reserved not just the truth, but the whole truth? Sir Francis Bacon (1561–1626) devised the scientific method but underestimated its occupational hazards PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition We See What We Expect and Want to See ▪ Why do people have so much trouble thinking critically? ▪ A natural and intuitive way of thinking about evidence worked better for hunter-gatherers than for today’s large-scale, complex societies. ▪ We tend to hold different kinds of evidence to different standards. ▪ Beliefs and desires shape which evidence to consider. ▪ We see what we expect and want to see. Copyright © 2023 by Macmillan Learning. All rights reserved ▪ We don’t consider what we don’t see. ▪ The skeptical stance ▪ Scientists constantly strive to make their observations more accurate and reasoning more rigorous. PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Hours Spent Partying or Studying at Some Canadian Universities The bar graph shows the hours per week that students at various Canadian universities reported they spend partying. Does this graph indicate that Queen’s, with the second-most hours, is full Copyright © 2023 by Macmillan Learning. All rights reserved of slackers? Why? Why not? PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition The Ethics of Science: Doing What’s Right ▪ The Tri-Council Policy Statement (TCPS) describes the core principles, based on respect for human dignity, that all research involving human participants must follow. ▪ First, research should show respect for persons and their right to make decisions for and about themselves without undue influence or coercion. ▪ Second, research should show concern for welfare which means that it should attempt to maximize benefits and Copyright © 2023 by Macmillan Learning. All rights reserved reduce risks to the participant. ▪ Third, research should be just, which means that it should distribute benefits and risks equally to participants without prejudice towards particular individuals or groups. PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Respecting People ▪ Some of the most important rules that govern the conduct of psychological research: ▪ Informed consent ▪ Freedom from coercion ▪ Protection from harm ▪ Risk-benefit analysis Copyright © 2023 by Macmillan Learning. All rights reserved ▪ Deception ▪ Debriefing ▪ Confidentiality PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Respecting Animals ▪ Canadian Council on Animal Care (CCAC) standards for the ethical use and care of animals in research. ▪ Replacement ▪ Reduction ▪ Refinement Copyright © 2023 by Macmillan Learning. All rights reserved PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition Respecting Truth ▪ Psychology, like all sciences, works on the honour system. ▪ Results are reported truthfully on what was done and what was found. ▪ Credit is ethically assigned. ▪ Data are shared. Copyright © 2023 by Macmillan Learning. All rights reserved PSYCHOLOGY Schacter | Gilbert | Nock | Johnsrude Canadian Sixth Edition