Chapter 2 – Psychological Research PDF

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Chapter 2 – Psychological Research Why is research important? •

Scientific research: critical tool to gain an objective understanding of something, through supporting evidence

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The process of consensus by the scientific community can last a while, there are always contradictive studies on the same topic It is important to have a critical eye when seeing a particular perspective, there could be contradictory – and more truthful – ones Facts: observable realities Opinions: personal judgments, conclusions, or attitudes that may or may not be accurate

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Margaret Floy Washburn (1871-1939): first woman to earn a PhD in psychology, researcher on animal behavior and cognition Mary Whiton Calkins (1863-1930): first-generation American psychology, opposed to the behaviorist movement, significant research into memory, established one of the earliest experimental psychology labs in the US Francis Sumner (1895-1954), “Father of Black Psychology”: first African American to receive a PhD in psychology (1920), focus on psychoanalysis, on racial bias, and on educational justice, one of the founders of Howard University’s department of psychology Inez Beverly Prosser (1895-1934): first African American woman with a PhD in psychology, research on education in segregated VS integrated schools, segregation of public schools is unconstitutional Horatio Piñero (1869-1919): founder of the first experimental psychology laboratories in South America Gunamudian David Boaz (1908-1965): first independent department of psychology in the University of Madras Narendra Nath Sen Gupta (1889-1944): first independent department of psychology in the University of Calcutta Mary Whiton Calkins: first female president of the APA (1905); by 1946 nearly one quarter of American psychologists are female Increasing diversity of contributors to the field of psychology Scientific method: process that advances scientific knowledge – Theories and hypotheses are tested against the real world (in form of empirical observations) – Empirical observations lead to more ideas that are tested against the real world à Circularity of the scientific process Deductive reasoning: ideas are tested in the real world – A generalization (hypothesis) is used to reach logical conclusions about the real world – If the hypothesis is correct, then the logical conclusions should also be correct

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Ex.: all living things require energy to survive (hypothesis); ducks are living things; therefore ducks require energy to survive (logical conclusion) à Since the hypothesis is correct, the conclusion is too; however, an incorrect hypothesis may lead to a logical but incorrect conclusion Inductive reasoning: real-world observations lead to new ideas (opposite direction to deductive reasoning) – Empirical observations are used to construct broad generalizations – The generalizations must be tested through deductive reasoning – Ex.: since apples, bananas and oranges grow on trees, all fruit grows on trees (false) Scientific process: formulation of a hypothesis through inductive reasoning, test of the hypothesis through deductive reasoning Theory: well-developed set of ideas that propose an explanation for observed phenomena, too complex to be tested all at once Hypothesis: testable prediction about how the world will behave if our idea is correct, “if-then” statement gap between ideas and real world – Created to test specific aspects of a theory – As specific hypotheses are tested, theories are modified and refined to reflect and incorporate the result of these tests – Must be falsifiable, being shown incorrect

Scientific method: deriving hypotheses from theories and then testing those hypotheses

Approaches to research •

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Many research methods, each with its strengths and weaknesses, each appropriate for certain types of research questions Correlational research: find a relationship between two variables (cause-effect), by performing an experiment Experimental research: much control over the variables of interest, artificial setting, in some cases problems with ethics Clinical or case study: studies that only focuses on one person or few individuals – Allows to gain more insight – Specific, hard to generalize (ability to apply the findings of a particular research project to larger segments of society)

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Naturalistic observation: observe a behavior in its natural context, without the participants to be biased (since when people know they are being watched, they tend to not behave naturally) – The researcher avoids interfering with the subjects, while observing them maintaining a distance – Validity and accuracy of the information, more realism – Difficult to set up, no control on when or if you have behavior to observe – Significant investments of time, money, and good dose of luck Structured observation: people are observed while engaging in set, specific tasks Observer bias: people who act as observers are usually closely involved in the research project and may unconsciously skew their observations to fit their research goals or expectations – Protect against it by having clear criteria established for the types of behaviors recorded and how those behaviors should be classifies Inter-rater reliability: measure of reliability that assesses the consistency of observations by different observers; comparison of observations of the same event by multiple observers to test it Surveys: lists of questions to be answered by research participants; easy collected data – Gather data from larger samples (subset of individuals selected from a population, the overall group of individuals that the researcher is interested in) – Study of the sample and generalize the findings to the population – Not able to collect the same depth of information on each person as in case studies – Calculate various measures of central tendency from the collected data, overall summary of the typical response – Responses are not always accurate (bias) Mode: most frequent response Median: the middle of a given data set Mean: arithmetic average of all data points; most useful measure; very sensitive to the effects of outliers

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Archival research: use of existing records to answer various research questions – The researcher never directly interacts with participants – Less investment of time and money to collect data – No control over what information was originally collected, the research question must then be fitted to be answered within the structure of the data sets – No guarantee of consistency between the records from one source to another (problematic to compare different data)

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Longitudinal research: gathering data repeatedly over an extended period – Often used to understand risk factors of diseases – Enormous number of people involved in these studies, then confidence in generalizing – Incredible time investment by the researchers and the participants, the results won’t be known for a considerable period – Substantial financial investment – Participants and researchers must commit during all that time à Attrition rates are high, and increase during the study (number of research participants due to dropouts) Cross-sectional research: comparison of multiple segments of the population at the same time – Short-term investment – Limited by differences that exist between the different generations (cohorts), that have nothing to do with age, but reflect the different social and cultural experiences

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Analyzing findings •

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Correlation: relationship between two or more variables, but not necessarily cause-effect (as one variable changes, so does the other) – If strong, it allows to predict behavior Correlation coefficient (r): number from -1 to +1 that indicates the strength and direction of the relationship between variables; if closer to +/- 1 stronger relationship, if closer to 0 weaker – Positive correlation: the variables move in the same direction – Negative correlation: the variables move in opposite directions Confounding variable: causes the systematic movement in the variables of interest (that’s why we can’t assume that if there’s correlation, there’s also cause-effect) Illusory correlations (or false correlations): when it is believed that relationships exist between two things, when there actually aren’t – May be involved in the formation of Confirmation bias: when you have a hunch about how something works and then look for evidence to support it, ignoring contradictory evidence The only way to establish causality (cause-effect) is by conducting a scientific experiment Experiment: testing a hypothesis, formulated through direct observation or review of previous research Experimental group: gets experimental manipulation, the treatment or the variable are tested Control group: isn’t manipulated Operational definition: precise description of the variables, define or operationalize their measurement – Aids people’s ability to interpret data and eventually their capacity to repeat the experiment Experimenter bias: possibility that the researcher’s expectations might skew the results of the study, so avoid telling the researcher who is in which group Single-blind study: one of the groups participants are unaware of which group they’re in, while the researcher who developed the experiment does know Double-blind study: both the researchers and the participants don’t know about the group belonging – Avoids placebo effect Placebo effect: when people’s expectations or beliefs influence or determine their experience in a given situation Independent variable: variable that’s manipulated or controlled by the experimenter – The only important difference the experimental and the control groups Dependent variable: variable measured by the researcher to see how much effect the independent variable had – It is expected that it will change as a function of the independent variable; what effect does the independent variable have on the dependent variable? Participants: subjects of psychological research, who actively participate in the process Random sample: subset of a larger population in which member of the population has equal chance of being selected; more representative of the larger population (if its sample is larger enough)

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Random assignment: all participants have an equal chance of being assigned to either group; makes sure that the population of the group doesn’t influence the outcome

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Manipulating an independent variable (as a person’s sex) can complicate many questions that psychologists want to address Quasi-experimental research: the clause-effect claims can’t always be made because the independent variable isn’t manipulable

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Statistical analysis: how likely any difference found between the two groups is due to chance – Differences are statistically significant if there’s a less than 5% chance of observing them if the groups weren’t different; limit the chances of making a false claim to 5% or less

à Assert that any significant difference in the findings is caused by the independent variables: random selection, random assignment, design that limits the effects of experimenter bias and participant expectancy; groups similar in composition and treatment • •

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APA: published a manual detailing how to write a paper for submission to scientific journals Scientific journals generally publish peer-reviewed articles aimed at an audience of professionals and scholars who are actively involved in research Peer review: look for a strong rationale for the research being described, a clear description of how the research was conducted, and evidence that research was conducted in an ethical manner; flaws in the study’s design, methods, and statistical analyses; how valuable the research is in advancing the discipline’s knowledge – Give the review to the researcher and to the journal Replication: the research is described clearly enough to allow to allow other scientists to replicate it; provides more evidence to support the original research findings Replication crisis: in the past few years some of the most well-known studies and scientists have produced research that has failed to be replicated by others; some claims that it is improving the ways in which science is conducted and how its results are shared with others Reliability: ability to consistently produce a given result; any instruments or tools used to collect data do so in consistent, reproductible ways Inter-rater reliability: degree to which two or more observers agree on what was observed) Internal consistency: degree to which different items on a survey that measure the same thing correlate with one another Test-retest reliability: degree the outcomes of a particular measure remain consistent over multiple administrations – Being consistent in a measurement does not necessarily mean that the measures were made correct (problem of the test per se) Validity: extent to which a given instrument or tool accurately measures what it’s supposed to measure Ecological validity: degree to which research results generalize to real-world applications Construct validity: degree to which a given variable actually captures or measures what it’s intended to measure Face validity: degree to which a given variable seems valid on the surface

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Experiments involving the participation of human subjects are governed by extensive, strict guidelines, designed to ensure that it doesn’t result in harm Institutional review board (IRB): committee of individuals made up of members of the institution’s administration, scientists, and community members – Reviews proposals with principles – Its approval is often required for the experiment to proceed (experiments involving humans) Informed consent form: written description of what participants can expect during the experiment, including potential risks and implications of the research; let participants know that their involvement is completely voluntary and can be discontinued without penalty at any time; guarantees that any data collected in the experiment will remain completely confidential Deception: purposely mislead experiment participants to maintain the integrity of the experiment, not to the point where it could be considered harmful Debriefing: used when deception is involved, upon conclusion of the study; giving complete, honest information about the purpose of the experiment, how data will collected will be used, reasons why deception was necessary, information about how to obtain additional information about the study Research on animal subjects: often rodents or birds are subjects (90%); many basic processes in animals are sufficiently similar to those in humans to be acceptable ad substitutes (for when humans would be considered unethical participants) – Researchers must design their experiments to minimize any pain or distress experienced by animal subjects Institutional Animal Care and Use Committee (IACUC): institutional administrators, scientists, veterinarians, and community members; committee that must ensure that all experimental proposals require the humane treatment of animal research subjects – Semi-annual inspections of all animal facilities to ensure that the protocols are being followed – No research can proceed without the committee’s approval

Professor’s notes Qualitative and quantitative research • •

Quantitative research: measured, numbers (test scores, rating) Qualitative research: not measures, ex. observed (interviews, case studies, sentence completion)

Quantitative studies •

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Descriptive: describing features of collected data – How many, min/max values, averages Correlational: relationships between variables; do not imply causation; used to predict trends

Experimental studies • •

The only type of research in which we can determine causation (studies done in lab) Control variables: control over other variables that may affect the results

Quasi-experimental studies •

People’s characteristics which aren’t withing the researcher’s control, come to the study with these traits

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– Non-randomized: we cannot assign to be 5’5’’ tall – No control over assignment: we cannot assign them to be 60-year-olds Assignment to Tx or Control: we can assign them to be in one group only (ex. be in either Tx or Control groups for PTSD) Alternative explanations (ex. their age is affecting the results and not the Tx per se)

Qualitative research • •

Inquiry: no Tx, no manipulation of variables Themes: we’re looking for main themes in people’s responses

Mixed-methods study (quantitative & qualitative) • •

Likert scale (ex. rate from 1 to 10 how likely you are to take this professor again) Interviews

From theory to research

Observation, hypothesis, experiment, tests, results

Methods of assessment • • • • •

Direct Observations Ratings by others Self-reports: questionnaires, interviews, stimulated recalls, think-alouds, dialogues Multiple methods Methods depend on research questions

à Reliability and validity IV and DV •

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Variable: abstract representation of a phenomenon – Independent variable (IV): the variable we hypothesize is the cause of a behavior à Manipulated – Dependent variable (DV): observed behavioral response à Measured Operational definition: explicit statements of abstract variables

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Extremely important part of the research; provides detailed process to permit critique or replication of study Operationalization: specification of instruments and procedures; how we are going to measure the variables

Basic and applied research •

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Basic research: driven by curiosity, knowledge-seeking, understanding mechanism behind phenomena (ex.: cognitive mechanism of processing) Applied research: focusing on a specific problem and its application in a real-world setting (ex.: effective tools in the of PTSD)

Theories – Things to be aware of to avoid misleading information and inappropriate practices •

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Who wrote this blog/article? For example: Is it a peer-reviewed article? Is it someone’s personal experience? How did they collect data? For example: Is the sample representative of the population it intends to study? Why did they publish it? For example: are they trying to advertise their product?

Common Sense What may seem as common sense to us, may seem the complete opposite to others. We all have different life experiences which lead us to perceive different things as logical or intuitively correct. Introspection At the beginning of the 20th century, there was a lot of hype about the methodology of introspection within the psychology community. Psychologists would examine their own thought processes and would develop theories on learning processes through these introspections. This method had several issues that make introspection a questionable method of validating psychological theories. Anecdotal Evidence Anecdotal evidence is an isolated story or example of someone’s personal experience to support or oppose a theory. The problem with anecd...