2.2 - Scientific Research Design Flashcards
What is Research Design & Influences how investigators. . .?
a set of methods that allows a hypothesis to be tested.
Influences how investigators:
1) organize the stimuli used to test the hypothesis
2) make observations
3) evaluate the results
Variables
is a property of an object, organism, event, or something else that can take on different values.
(ex. how frequently you laugh)
Operational Definitions
are the details that define the variables for the purposes of a specific study.
(ex. score on the “Coping Humour Scale”)
Data
the information scientists record when they
collect observations about the variables of interest.
(ex. the scores of participants on the “Coping Humour Scale”)
Descriptive Research
answers the question of “what” a phenomenon is (describes its characteristics).
(ex. How many words can the average two-year-old speak?)
Case Study
is an in-depth report about the details of a specific case.
(ex. describe an individual’s history and behaviour in great detail rather than developing a hypothesis and testing in one a # of different individuals)
* used for/limited to individuals with uncommon characteristics or been through unusual experiences.
* useful in describing symptoms of psychological disorders and detailed descriptions about successes & failures in treatment
* used to find similarities between different concepts
(ex. studied one individual for 16 weeks & documented how and when changes occurred and effects of the treatment. If it were more than a single individual, findings cannot be generalized to other individuals and situations)
Strength : Yields detailed info, often of rare conditions or observations
Limitations : Focus on single subject limits generalizability
Phineas Gage
- most famous case study in psychology (& neurology)
- iron rod penetrated his brain & caused major damage but he survived
- after affects : became impulsive, inconsiderate, indecisive, impatient
- Dr. Harlow stuck his finger into the hole in Gage’s head & discovered the damage was located in the frontal lobes of the brain (area involving decision making & emotional regulation)
- Gage’s case study allowed for better understanding of the role of the frontal lobes & the problems that occur when damaged
- taught us how different areas of the brain influence particular behaviours
Amygdala
- a fear centre in the brain
- essential for emotional info to grab our attention
(ex. attention always drawn to a spider crawling across your ceiling)
PTSD
Postraumatic Stress Disorder
a condition in which specific stimuli trigger intense emotional responses due to a previous traumatic event.
Brandon Wagar & Paul Thagard
created a computerized neural network that used both cognitive and emotional info to produce simple decisions.
Experiment : altered parameters so that the frontal lobe node did not function
Result : network’s response became dependent upon emotional impulses (similar to Phineas Gage)
Naturalistic Observations
to unobtrusively (without subject’s knowledge) observe & record behaviour as it occurs in the subject’s natural environment.
*researchers must pay attention to specific variables and use operational definitions
Strength : allows for detailed descriptions of subjects in environments where behaviour normally occurs
Limitations : Poor control over possibly influential variables
Self-reporting
a method in which responses are provided directly by the people who are being studied, typically through face-face interviews, phone surveys, paper and pencil tests, and web-based questionnaires.
allows for assessment of attitudes, opinions, beliefs, abilities
When psychologists observe behaviour & record data in the environment where it normally occurs they are using ______.
Naturalistic Observation
Any property of an organism, event, or something else that can take on different values is called ______.
A variable
A psychologist is completing a naturalistic observation study of children’s aggressive behaviour on a playground. She says that aggression is “any verbal or physical act that appears to be intended to hurt or control another child.” She then goes on to list specific examples. It appears that the psychologist is attempting to establish a(n)?
Operational Definition
Correlational Research
involves measuring the degree of association between two or more variables.
(ex. What is the average education level of people in every country in the world?)
* presented with scatterplot
- correlations take a direction
- if correlations are positive, the two variables change in the same direction (ex. if one value increases, the other does as well)
- if correlations are negative, the value of one variable increases and the value of the other decreases
- correlations have magnitude or strength
- refers to how closely the changes in one variable are linked to changes in another variable
(ex. if variable A goes up 1 unit, variable B also go up one unit) - this magnitude = correlation coefficient
Strength : shows strength of relationships between variables
Limitations : Does not allow researcher to determine cause-and-effect relationships
Correlation Coefficient
a measure of association
- not a measure of causuality
- correlation =/= causation
(ex. sense of humour is associated with good health, they have a positive correlation relationship, but that does not mean humour is responsible for good health)
- correlation coefficient of 0 = no relationship between the two variables
- +1.0 = very strong positive correlation
- -1.0 = very strong negative correlation
- +1.0 & -1.0 have equal magnitude or strength, but have different direction
Third Variable Problem
the possibility that a third, unmeasured variable is actually responsible for a well-established correlation between two variables
(ex. negative correlation between sleep and irritation, there could be third variables that account for this relationship - stress, diet, etc could have caused both increased irritability and sleep loss)
Illusionary Correlations
relationships that exist only in the mind, rather than in reality
Which of the following correlation coefficients show the strongest relationship between two variables?
A) +0.5
B) -0.7
C) +1.1
D) +1.0
-0.7
This is a strong negative correlation. The strength of the relationship is strongest because it is closer to -1.0 than either +0.5 or +1.0. Correlation coefficients cannot go above 1.0
What does it mean to say that two variables are negatively correlated?
An increase in one variable is associated with a decrease in the other
Imagine Dr. Martin finds that a sense of humour is positively correlated with psychological well-being. From this, we can conclude that?
A) Humour causes people to be healthier
B) Health causes people to be funnier
C) People who have a good sense of humour tend to be healthier
D) People who have a good sense of humour tend to be less healthy
People who have a good sense of humour tend to be healthier
*correlation is not a cause!
Experimental Research
- min. of two variables
- random assignment of participants
- experimenter’s control over variables being studied
Strength : tests for cause-and effect relationships; offers good control over influential variables
Limitations : Risk of being artificial with limited generalization to real-world situations
Random assignment
a technique for dividing samples into two or more groups in which participants are equally likely to be placed in any condition of the experiment