chapter 4 Flashcards
Steps in scientific method
- Define problem and hypothesis
- Choose and implement method
- Collect and analyze data
- Draw conclusions
Hypothesis:
statement predicting what will happen is a study
Null hypothesis:
prediction that there is no relationship between phenomena
Variables:
factor that can vary (dependent or independent)
Operationalization:
the way we measure and manipulate variables (ex: how they are defined for that study
Case studies:
detailed history of unique individuals with a psychological disorder
Advantage/Disadvantages of case studies
Advantage:
- Able to study rare problems
Disadvantages:
- Cannot be generalized to larger population
- Lacks objectivity because different researchers might notice or treat patient in different ways
Correlational study:
examines the relationship between an independent and dependent variable (without variable manipulation)
Continuous:
two or more continuous variables measured
Group Comparison:
two or more groups compared on a variable
Cross sectional:
participants assessed at one point in time
Statistical significance:
- Index of how likely a result is due to chance
- p<.05 is the goal which means that the probability is less than 5/100 that the result occurred by chance
Longitudinal:
participants assessed more than once over time
Third variable problem:
an unmeasured third variable that is associated with independent and dependent variables that may be affecting the results
Random sample:
every person in population has equal chance of being selected
Sample:
group of people taken from population we want to study
Representative Sample:
highly similar or representative of population we are studying
Comparison Group:
participants should match the treatment group in every variable except the one being tested for
Advantages/disadvantages of correlational research
Advantages:
- focus on real world situations not lab ones
- Longitudinal designs determine differences between groups before event occurs
- Ensures differences cause event and event does not cause differences
- Good external validity
Disadvantages:
- Longitudinal studies are expensive and time consuming
- Cannot infer causation
- Third variable problem
Epidemiological studies:
a study of frequency and distribution of a disorder
Prevalence rate:
the proportion of the population that has the disorder at a given point or time
Incidence rates:
Number of new cases in a disorder
Risk factors:
conditions with a higher risk of a disorder
Advantages/disadvantages of epidemiological research
Advantages:
- Provide info for who’s at highest risk and we can use this to test hypotheses about why they are at higher risks
Disadvantages:
- Cannot establish causation
- Third variable problem
Human laboratory studies:
Expose participants to an event in a lab and then determine its impact
Internal validity:
changes in the DV can be confidently attributed to manipulation of the IV
Experimental group:
the group that receives the independent variable
Control group:
the group that does not receive the independent variable
Random assignment:
all participants have an equal chance of being in the experimental or the control group
Demand characteristics:
participants guess the study’s purpose and change their behavior
- Solutions: Can use filler measures, Cover story (basically deception), Double-blind experiments
Advantages/disadvantages of laboratory research
Advantages
- Higher control
- Random assignment
Disadvantages
- External validity
- Ethical limitations
Therapy outcome studies:
experimental studies designed to test whether a specific therapy, a psychological therapy, or a biological therapy reduces psychopathology in individuals who receive it
Simple control group:
do not receive treatment but are still tracked
Waitlist control group:
- they receive treatment after the experimental group
- Come to a study as a control group, and when the experiment is over they become the experimental group and receive treatment
Placebo control group:
receive an inactive treatment (most commonly used to test effectiveness of drugs)
Advantages/disadvantages of therapy outcome studies
Advantages:
- Provide help to people in distress
Disadvantages:
- Ethical considerations for control group
- Which aspect of the therapy worked?
- Balancing patient’s needs with standardized treatment
- External validity
Single-case experimental design:
one or few individuals are studied intensively
ABAB design:
treatment introduced, withdrawn, and then reinstated
Multiple baseline design:
- give treatment to the same individual but in different settings or at different points in time
- Give treatment to different individuals at different points in time
Advantages/disadvantages of single-case experimental design
Advantages: more intensive assessment of participants
Disadvantages: generalizability is limited and cannot test all hypotheses
Genetic studies:
identify genetic factors associated with psychopathology/ the degree to which genes play a role in a disorder
Family history studies:
identify people who have disorder, identify control group, trace the family tree
Twin studies:
compare rates of a disorder among monozygotic and dizygotic twins, and determine concordance rate
Adoption studies:
identify people with a disorder who were adopted shortly after birth, determine the rates of a disorder among biological relatives and adoptive relatives
Molecular genetic studies:
comparing DNA of people who have a disorder with a sample who do not to find a genetic characteristic or marker that might cause this disorder
Concordance rate:
the probability that both twins will have a disorder
Linkage analysis:
identify other characteristics that co-occur with the disorder and have known genetic markers
Cross-cultural studies
- Examines similarities and differences of psychopathology between cultures
- Challenges: variation in the meaning of concepts and theories, translating assessment tools across cultures, language barriers
Meta Analysis:
Statistical technique to summarize results across several studies
Steps:
1. Literature search
2. Transform results of each study into common statistic so that tey can be compared
3. Examine average effect size across studies
advantages/disadvantages of meta analysis
Advantages:
- Provides more power to find out significant effects
Disadvantages:
- Problems with methodology
- File drawer effect: Studies that do not support the hypothesis they are designed to test are less likely to get published
