Week 7: Psychological Discovery: Sampling Procedures, Descriptive and Correlational Research Methods Flashcards
DONE!
Why do we want a sample to be “representative”?
So that the research findings are generalizable
When is a sample considered representative?
If the characteristics of the sample approximate that of the population
If the characteristics of the sample do not approximate that of the population, what is that sample considered to be?
Biased
What are the two ways we can sample individuals from a population?
Probability and non probability sampling
What is probability sampling?
Each member of the population has a known probability of being selected to be part of the sample.
How many types of probability sampling is there?
Three
What are the types of probability sampling?
- Random Sampling 2. Stratified Random Sampling 3. Cluster Sampling
What is random selection?
A method of generating a random sample in which each member of the population is equally likely to be chosen as part of the sample.
What are the benefits of random sampling?
Each member of the population is equally likely to be chosen as part of the sample.
True or false: if a population is made up of 70 % women and 30 % men, the sample can be 50 % women and 50 % men?
False. The sample must be similar to the population, therefore it should be 70% women and 30% men.
If needed to take into account different subgroups of people in the population, what sampling method could we use?
Stratified Random Sample
What is stratified random sampling?
A sampling technique designed to ensure that subgroups or strata are fairly represented.
What is a common sampling method used with large populations?
Cluster Sampling
What is cluster sampling?
A sampling technique in which clusters of participants that represent the population are used. Participants are already apart of a group or “cluster” e.g students enrolled in specific classes at university
What is nonprobability sampling?
A sampling technique in which the individual members of the population do not have an equal or known likelihood of being selected to be a member of the sample. It is the less expensive, easy option to generate samples, so often used.
What are the two types of nonprobability sampling called?
Convenience sampling and quota sampling
What is convenience sampling?
A sampling technique in which participants are obtained wherever they can be found and typically wherever is convenient for the researcher.
What is quota sampling?
Similar to what stratified random sampling is to probability sampling, it is a sampling technique that involves ensuring that the sample is like the population on certain characteristics but uses convenience sampling to obtain the participants. We do not sample from the population randomly, but take participants wherever found. Not much effort put into creating representative sample or where members of population have a known chance of being selected for the sample.
What is quantitative research?
Research that examines variables that typically vary in quantity (size, magnitude, duration, or amount). Data obtained from these measurements are usually numerical scores that can be summarised, analyzed, and interpreted using statistical procedures.
What is qualitative research?
It involves careful observation of participants (often including interaction with participants), usually accompanied by extensive note taking. Resulting in a narrative report meant to describe and interpret the phenomenon being studied. Without the use of statistics.
What is the main difference between qualitative and quantitative research?
The type of data they produce.
After you have identified a new idea for research, formed a hypothesis, decided how to define and measure your variables, and determined which individuals should participate in the study and how to treat them ethically, what is the next step?
To select a research strategy
What does a “research strategy” refer to?
The general approach and goals of a research study - what you hope to accomplish. A research strategy is determined by the kind of question the research study hopes to answer.
What are the three types of DESCRIPTIVE methods psychologists use?
- Observational method 2. Case Study methods 3. Survey method
What are the two types of observation method psychologists use?
Naturalistic observation - observing the behaviour of humans or animals in their natural habitat Laboratory observation - Observing the behaviour of humans or animals in a more contrived and controlled situation, usually the laboratory.
What is a “case study method?”
An in-depth study of one or more individuals. Involves describing the individuals being studied.
What is a “survey method”?
Questioning individuals on a topic or topics and then describing their responses. Surveys can be administered by mail, over the phone, on the internet, or personal interview. Concerns over survey methods are if sample is representative of population - hence why random sampling is an advantage.
What is a “random sample”?
A sample achieved through random selection in which each member of the population is equally likely to be chosen.
What are the names of the two methods that allow researchers to describe behaviours and predict one variable to another?
Correlational and quasi-experimental methods
What is a correlational method?
A method that assesses the degree of relationship between two variables. e.g height and weight are directly correlated (increase in height = increase in weight - BUT, being a certain height does not CAUSE you to be a certain weight)
True or false: if two variables are correlated, there must be a causal relationship between the variables?
FALSE. Correlation does NOT imply causation. A correlation simply means that the two variables are related in some way.
In correlational methods, what does a “positive relationship” mean?
A relationship between two variables in which an increase in one variable is accompanied by an increase in the other variable. (e.g increase in height is positively related to an increase in weight)
In correlational methods, what does a “negative relationship” mean?
A relationship between two variables in which an increase in one variable is accompanied by a decrease in the other variable. (e.g as a mountain elevation increases, temperature decreases.) Allows us to predict one variable to another.
What is a quasi-experimental method?
Research that compares naturally occurring groups of individuals; the variable of interest cannot be manipulated. E.g Examining alcohol consumption in fraternity students versus students not in organisation. We do not have control over this - we are simply looking for difference in the alcohol consumer occurring naturally between these two groups.
What is subject (participant) variable?
A characteristic inherent in the subjects that cannot be changed.
What is the main thing missing when we use correlational or quasi-experimental methods?
CONTROL.
True or false: when we use predictive methods, we systematically manipulate variables of interest?
FALSE. WE only measure variables of interest. So while we may observe a relationship between variables, we cannot conclude there is a causal relationship because there could be alternative explanations for these relationships.
What is an “alternative relationship”?
The idea that it is possible that some other, uncontrolled, extraneous variable may be responsible for the observed relationship.
What is the “experimental method”?
A research method that allows a researcher to establish a cause-and-effect relationship through manipulation of a variable and control of the situation.
What is an independent variable?
The variable in a study that is manipulated by the researcher
What is a dependent variable?
The variable in a study that is measured by the researcher
What is the control group?
The group of subjects that does not receive any level of the independent variable and serves as the baseline in a study
What is the experimental group?
The group of subjects that receives some level of the independent variable.
What is a random assignment and why is it used?
Assigning subjects to conditions in such a way that every participant has an equal probability of being placed in any condition. It is used to gain as much control as possible and eliminate any alternative explanations.
