3) Scientific Methods Flashcards
What are the scientific methods used for?
- Assess claims
- Make decisions
What is a hypothesis?
An exact prediction about outcomes
What are operation definitions?
- An exact definition for the purpose of the study
- Words that do not necessarily have a meaning
- May vary from study to study
What is a naturalistic observation?
A descriptive research method in which researchers observe and record behavior in its natural setting, without attempting to influence or control it
What is the issue with naturalistic observations?
Reliability “cross-validation”
What is a case study?
Study of ONE subject (person) in depth
Are case studies published often? Can data be generalized?
- Not published much, unless its incredible or unusual
- Data cannot be generalized
What kind of studies do psychologists use?
Case studies
What are surveys?
Data collection tool used to gather information about individuals
What is the key to surveys?
Sampling; selecting a portion of the population
What does sampling need to be?
- Random
- Every single person in a population needs to have an equal chance of being selected for the research sample
Can you use open-ended questions in surveys?
- Only if you have a small sample
- If not, you’ll end up with too many different answers
What is a likert scale?
- Statements are used
- Strongly agree, agree, strongly disagree
Why is anonymity important in research?
People will tell you what you want to hear
What is a longitudinal study?
Observational research method in which data is gathered for the same subjects repeatedly over a period of time
What are the upsides and downsides of longitudinal studies?
- Reliable
- Takes an enormous amount of time; difficult to obtain research grants
- Subject attrition
What are longitudinal studies best used for? Why?
- Infants and young children
- Since they are growing quickly, studies can be done quickly
What are cross-sectional studies?
Observationalstudythat analyses data collected from a population, or a representative subset, at a specific point in time
What is the upside of a cross-sectional study?
You can accomplish a 10-year longitudinal study in two hours
What is the basic assumption of a cross-sectional study?
The 8 year old accurately reflects what the 6 year old would reflect in two years
What is a correlation?
- Compares the relationship between two sets of data
- Does NOT indicate cause-effect; simply states that they are related
What is the correlation coefficient? What are the ranges?
- 1.00 to 1.00
1. 00 is a perfect correlation; generates a linear graph
Is a negative correlation low?
- Not necessarily
- r.= -0.93 is high; its just that one value increases as the other value decreases
Give an example of a negative correlation.
The more you exercise, the more the body weight goes down
What is the use of correlation?
If there is an established correlation, if you know one score, you can predict the other
What is an experiment?
Tries to establish cause-effect
What is the independent variable?
- Variable (effect) BEING studied
- Something that one group of people do that another group of people don’t
Does the dependent variable affect the independent variable, or the opposite?
The independent variable affects the dependent variable
Is before and after research valid?
NO, since you need a control group
What is blind research?
Information about the test is masked (kept) from the participant, to reduce or eliminate bias, until after a trial outcome is known
What is double-blind research?
If both tester and subject are blinded, the trial is called adouble-blind experiment
What are main effects?
The effect of one of your independent variables on the dependent variable, ignoring the effects of all other independent variables
What are interaction effects?
When the effect of one independent variable on the dependent variable changes depending on the level of another independent variable
What is reliability?
- Consistency of the test data
- Refers not only to the people, but to the test itself
How do you measure reliability in terms of numbers?
- Test Retest measure
- Correlation coefficient but rather than comparing one thing to another, we’re comparing Trial 1 and Trial 2 of the same experiment
- If the test is 100% reliable, r.=1.00
What is validity?
Refers to a test’s ability to measure what its supposed to measure
Why are statistics important?
- Objectively describe behaviour
- Help us make decisions
- Establish norms
- Standardized tests
What is the median?
Value separating the higher half of a data sample from the lower half (middle value)
Why would you want the median over the average?
To reduce any anomalies or outliers
What is the mode?
Value that appears most often in a set of data
The mode is most often non-_______
parametric
What does non-parametric mean? Give examples.
- Gathering data without numbers
- Which fast food restaurant is your favourite?
What is the mean/average?
Sum of the scores divided by the number of cases
What is the problem with the mean?
- Does not tell us the raw range of scores that make up the mean
- Two groups can have the same mean, but very different raw data
How do you solve the problem with the mean?
Standard deviation
What is the standard deviation?
- Number calculated from the raw scores that tells us about the spread of the scores that make up the mean
- The larger the standard deviation the greater the spread
What does the standard deviation tell us?
Tells us how far the mean is “OK” and how far from the mean is “abnormal”
What percent corresponds between the mean and 1SD deviation?
34.1%
What percent corresponds between the 1SD and 2SD deviation?
13.6%
What percent corresponds between 2SD and 3SD deviation?
2.1%
