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Transcript of Psychological Research Strategies Module 2. Why is Research Important? Gives us a reliable,...
Psychological Research Strategies
Module 2
Why is Research Important?
Gives us a reliable, systematic way to consider our questions
Helps us to draw logical, supported conclusions
* Not all will conduct research, but all have to evaluate its relevance
Research Methods
Example research topic: Does listening to music through headphones affect
studying?
What does common sense say?
Observation
Benefit: simplest scientific technique Problem: bias Two Types of bias:
Researcher bias – observation may be influenced by what they want/expect to discover
Participant bias – may respond a certain way because: know they’re being observed believe they know what the
researcher wants
What do you see?
Ways to reduce bias:
Researcher – finding ways to rely less on observers’ opinion
Participant – using naturalistic observation – naturally occurring settings
Case Studies
one person is studied in depth in the hope of revealing universal principles
Problems: bias can’t always apply results of one study to other
situations
Sometimes necessary for ethical reasons
Correlational Study
Reveals the extent to which two variables are related to each other
Examples: Is there a relationship between… diet and health? training techniques and success in sports? studying and better grades?
Uses of Correlational Studies
does not prove that a cause-and-effect relationship exists
tell you onlyonly that variables are related, not why they are related
Useful for making predictions – the stronger the correlation, the more accurate your prediction will be
Correlation Positive Correlation – both variables
increase or decrease together Examples: height & weight, studying effectiveness
& frequency of wearing headphones
Perfect Positive Correlation Moderate Positive Correlation
Correlation Negative Correlation – one variable
increases while the other decreases Example: hours spent watching TV & GPA, studying
effectiveness & frequency of wearing headphones
Perfect Negative Correlation Moderate Negative Correlation
Surveys
Goal: discover the self-reported attitudes or behaviors of a sample of people using questionnaires or interviews
Benefits: efficient, can reach large crowds
Problems: bias in wording, social desirability
Surveys
For results to be relevant to the population: Random sample – every member of the
population has an equal chance of being selected
Adequate number of participants – determined by mathematical formulas; larger samples = more relevant results
Longitudinal and Cross-Sectional Studies both study how individuals change during life
Longitudinal studies – follow the same group of individuals for many years Benefits: abundant data Problems: expensive, difficult to conduct = rare
Cross-sectional studies – compare people of different ages at one time Benefits: more efficient Problems: changes in time can affect results
Experiments
Purpose: onlyonly method that allows you to establish a cause-and-effectcause-and-effect relationship
Hypotheses and Operational Definitions
1st step: form a hypothesis – testable prediction of the experiment’s outcome
operational definitions of the variables – putting them in a more specific form so they can be precisely measured
Operational Definitions Example
Which of these example hypotheses has provided operational definitions?
A) “Headphones influence concentration in class”
B) “Students assigned to wear headphones in class will have higher average grades at the end of the quarter than students banned from wearing headphones.”
* WS w/ partner
Independent and Dependent Variables
Two variables of a hypothesis:1. Independent variable (IV): the variable that should
cause something to happen
2. Dependent variable (DV): the variable that should show the effect (or outcome) of the IV
IV & DV Example “Students assigned to wear headphones in
class will have higher average grades at the end of the quarter than students banned from wearing headphones.”
What are the independent and dependent variables?
IV = presence or absence of headphones
DV = participants' average end-of-quarter grades
Groups & Random Assignment
Most experiments have two groups: Experimental group – exposed to the IV
(headphones) Control group – not exposed to the IV
(no headphones)
Critical feature: people placed in groups by
random assignment – assigning by chance
Confounding Variables
Variables other than the IV that could produce a change in the DV
Examples of individual differences for our example:
Confounding variables can be controlled for by random assignment – can assume that factors will balance out evenly across both groups
• amount of sleep• personal problems• health• quality of teachers
Control for Other Confounding Variables:Environmental Differences
Other types of confounding variables: Environmental differences Expectation effects
Control for environmental differences by making sure both environments are the same (temperature, lighting, noise conditions)
Control for Other Confounding Variables:Expectation Effects
Control for expectation effects by: Blind procedure - participants don’t know
hypothesis until after data is collected
Double-blind procedure – the people collecting the data & participants don’t know the expected outcome
Placebo – nonactive substance or condition that
is given instead of a drug or active agent (all drug studies)
Data Analysis
Run the experiment & collect the data, then analyze the numbers using statistics
Statistically significant – the possibility that the difference between groups would occur by chance alone is not more than 5%
Replication
Results must be replicable (can be reliably repeated) to prove a cause-and-effect relationship between the IV & DV
Ethics: Human Research
4 Ethical Principles Guiding Human Research:1. Informed consent – about nature of research & risks
2. Right to be protected from harm and discomfort
3. Right to confidentiality – can’t release data about individual participants
4. Right to debriefing – full explanation of research when involvement is done
Ethics: Animal Research
Must have clean housing, adequate ventilation, and appropriate food, be well-cared for