Experimental Psychology: Scientific Methods

• Experimental psychology is a method of studying psychological phenomena and processes
• The experimental method aims to account for activities and mental processes in animals and humans
• It discovers laws that describe manipulable relationships
• Generally connotes areas of psychology using the experimental method

Scientific Approach

• Psychology researches psychological processes underlying behavior via psychological science
• Science comes from the Latin "scientia," meaning knowledge, with content and process meanings
• Its content includes known facts, like those in psychology or chemistry courses
• As a process, it includes systematic data gathering, noting connections, and providing explanations

Scientific Research Methods

• Psychology relies on scientific research, collecting data in experiments and controlled conditions
• Methods involves surveys in the community, observing behavior in natural settings
• It includes psychological tests or personality observation during patient sessions
• Scientific criteria are used to evaluate data from experiments, settings, or therapy sessions

Scientific Methodology

• Everyday nonscientific data shapes expectations and beliefs
• It directs behavior, which is called "commonsense psychology"
• Gathering data systematically and impartially is constrained through information sources and inferential strategies, which can be biased, and potentially make information unreliable or imperfect

Nonscientific Data

• Data sources include friends, relatives, people in authority or admire, and media reports
• Historically, knowledge is acquired through authority, rationalism, intuition, and the scientific method
• Beliefs tend to become stable, overlooking disconfirming instances and seeking confirmatory behavior, known as confirmation bias

Nonscientific Inference

• Inference involves inferring as passing from judging as true to another whose truth is believed to follow from that of the former
• Something inferred is a proposition arrived at by inference, based on premises and conclusions
• Commonsense psychologists are trait theorists when explaining others' behavior
• There is bias to disregard situational data, generally more accurate when familiar with someone
• Perceiving traits predicts behavior, but can overestimate consistency, leading to stereotyping

Gambler's Fallacy

• Gambler's Fallacy is a good example of nonscientific inference
• Believing a slot machine is due for a payoff after not paying out for a while despite each game being independent
• Fallacy incorporates guile, deceptive appearance (deception) and false mistaken ideas
• It utilizes erroneousness and sometimes has plausible arguments using false or invalid inference

Overconfidence Bias

• Overconfidence bias involves predictions and explanations feeling more correct than they actually are
• Increased confidence with more available data, whether accurate or not
• The scientific method uses gathering information, answering questions, explaining relationships and communication

Modern Science

• Psychologists assume behavior has a natural order, making it predictable
• Alfred North Whitehead (1861-1947) called the scientific mentality based on faith in an organized universe
• He believed in order is essential to science, necessitating methods for investigation
• Research psychologists believe specifiable causes exist for behavior
• Causes can be discovered through research, called determinism

Gathering Empirical Data

• Assumes universal order, described systematically by collecting empirical, observable data which is verified through investigation

Seeking General Principles for Behavior

• Scientists propose general principles (laws or theories) to explain observations
• Laws apply generally to all situations
• Due to having limited information, understanding advances by using an interim explanation called a theory
• Theories unify diverse scientific facts into a scheme or rules that predict behavior
• Hypothesis formulates a testable prediction
• Sir Karl Popper (1902-1994) proposed science progresses through better theories

Good Thinking Principles

• It Includes being open to new ideas, even those contradicting prior beliefs
• Follows logic where conclusions will follow from data, wether predictions are agreed upon or don't
• Parsimony is a principle, also called Occam's razor, advises using the simplest explanation until conflicting data proves it wrong

Self-Correction

• Science changes as new information is obtained, reevaluating old facts with new evidence
• A "weight-of-evidence" approach where more evidence increases confidence in a theory
• Old explanations are replaced when evidence supports a different explanation

Publicizing Results

• Scientists exchange information through professional groups and conferences
• More scientific papers are published annually
• Continuous exchange is vital to science
• Working in isolation would miss findings and waste effort duplicating failures and successes

Replication in Procedures

• Procedures can be repeated when data is gathered objectively and by good thinking
• Findings obtainable by one researcher have limited value
• Without recreating conditions from the original results, the study cannot be replicated
• Replication of findings raises confidence from the ability of other researchers repeating findings

Objectives of Psychological Science

• There are four major objectives of research : description, prediction, explanation, and control.

Objective: Description

• It involves a systematic, unbiased account of observed behaviors
• Good descriptions give greater knowledge of what behaviors will be like based on what is observed
• Includes research design, descriptive research, case studies, field study, surveys, and interviews

Objective: Prediction

• It refers to the capacity to know when certain behaviors are expected to occur
• Involves predicting events based on identified conditions that behaviors link to

Research Designs

• Includes correlational and quasi-experimental designs

Objective: Explanation

• It includes knowing the conditions that reliably reproduce a behavior

Objective: Control

• It refers applying knowledge about behavior that is learned
• Affect change or improve behavior.
• Research design utilizes (True) experimental research design; two-fold: testing the specified conditions' effects and changes.

Applied and Basic Research

• Applied Research is designed to solve real-world problems
• Basic Research designed to test and explain phenomena in humans and animals.

Scientific Method

• Involves gathering information rationally and basing conclusions on evidence
• Three main tools: observing and defining observations, measurement, and experimentation

Systematic Observation

• Involves systematic noting and recording of the events
• Only observable can be studied scientifically
• Internal events can be studied if observable signs are developed
• Use the same system for consistent observation

Measurement Procedures

• It is assigning numerical values to characteristics per conventional rules
• Representing higher anger or depression levels as numbered scales
• Measurements must be consistent across conditions
• Numbers, or scores, are needed to represent amounts of behavior

Features of Quantitative and Qualitative Research

• Assigning numbers to represent feature observations defines quantitative research
• Recording observations descriptively uses words instead of numbers defines qualitative design

Hypothesis

• It is a process that tests a hypothesis that events will occur based on conditions
• Manipulating the setting verifies predictions about behavior under conditions
• Predictions should be testable(hypothesis) through the 3 requirements:
  • Procedures for handling the setting
  • The predicted visible outcome
  • Able to measure the outcome
• Experimentation should be objective
• It considers ethical reasoning for studying

Comparing Treatment Conditions

• Psychology experiments create antecedent conditions called treatments
• Treatment conditions should be compared systematically and scientifically
• Treating subjects to different antecedents
• Exposing antecedents measure if the treatment effect predictably differ
• Specifying antecedents explains behavior

Explanation in Psychological Science

• Explanation means specifying conditions of an event or behavior
• Antecedent conditions precede the event or behavior trying to be expalined
• Identifying behavior antecedents lead to the expectation of a particular behavior when those same antecedents again occurs.

Psychology Experiment

• It is a controlled procedure applying two treatment conditions to subjects
• Measured behaviors test hypotheses about treatment effects on behavior
• Experiments needs at least two treatments to compare varied behavior under conditions
• Procedures in psychology experiment is carefully controlled so that what is intended is measured
• Subject characteristics receiving different treatments is important to be controlled
• Equivalency is preferred to the subjects of what is in treatment
• An experimental design in which subjects receive one kind of treatment is called a between-subjects design.

Subject Differences

• It might gets ruled out with the treatment to be presented
• Can measure treatments as effect if you were to find all treatments after it is presented
• Designs in experiments must be within-subjects designs
• Successful experimentation controls the subject
• Random experiment design provides assignment to each subject

Achieving Control

• It involves random subject assignment to conditions (or within-subjects design) presenting an identical conditions
• Maintains constant environment, procedures, instruments as measuring device so that only specific treatments conditions can change

Cause and Effect of Psychology experiments

• The greatest value determines the experiments between cause-and-effect relationship
• The XYZ of cause and effect leads through the particular behavior.
• The difference we established through what we established between temporal relationship cause and its potential effect

David Hume

• He argued that can never establish causality from temporal relationships (1711-1776)
• It does not necessarily mean causing, but rather just being present first

Sufficient Conditions and Factors

• Gaining control over factors in a experiment helps understand behavior of what experiment tests
• Cause-and-effect relationships through research is usually only sufficient conditions
• The scientific method looks at a practical approach for reliance on sufficient causes
• Psychology emerged in the late 1800s with Wilhelm Wundt (1832-1926)
• Wundt is credited as the first experimental psychologist, founding his Leipzig laboratory in 1879
• Wundt used scientific methods (observation, measurement, experimentation) to study sensory experience.
• An early student named G. Stanley Hall opened the first psychology laboratory in the United States in 1883 at Johns Hopkins University
• Early academic U.S. psychology was in philosophy departments under mental philosophy

Consciousness and Sensory Experience

• Mental philosophy studied consciousness and mental processes, as it has a premise that the human mind begins as a blank slate
• Then it gains knowledge through sensory experience.
• Mental philosophers studied the five senses through introspection, observation
• Reporting thoughts and feelings is called phenomenology