Research Designs: Experimental Methods, Correlational Studies, Case Studies
-used to determine a cause-effect relationship (cause and effect relationship means whether A influences B or not; A could be like amount of milk drank each day, B could be height). So we want to see if drinking milk influences one height.
Two area must be fulfilled when performing experimental studies:
1: Manipulation of the independent variable
2: ensuring that participants in each experimental condition are equivalent to each other at the beginning of study; that they have equal chance of getting tested.
Ā Ā Ā Ā Ā This could be done through the following methods:
Random Assignment used if manipulation is between groups. For example, Girls and boys.
Counterbalancing: If manipulation is within group.
Question to consider: What are examples of when to use random assignment of counterbalancing?
The experimental group has to drink a certain amount of milk over a course of their life. Group 2, the control group does not drink milk.
Over time, we see if the average height of group 1 is any different from the average height of group 2. If yes, then we possibly have a causal effect.
-a statistical procedure used for determining whether or not there is a relationship between two variables.
- a major advantage of correlational studies is that they allow us to indentify relationships among variables as they occur naturally (no manipulation of the variables like done in experimental studies.Ā
-example of correlational studiesĀ would be comparing people who likes to study with or without noise (music) with their extraversion or introversion.
Ā -comparison between self-esteem rated through S-data and O-data
Ā -achievement motivation and grade point average
Ā -self esteem and happiness
Ā -extraversion and emotional stability
Terms related to correlational studies:
-Correlation coefficient (magnitude and direction to be considered)
Note: Correlational studies does not infer a cause-effect relationship (eg. because he/she's higher in self-esteem does not mean he/she's more happy)
This is because of two reasons:
Ā -Directionality Problem: Unlike experimental studies, we don't manipulate or try to change anything. As a result, when we compare something like self-esteem with happiness, we don't know for sure whether it is higher self-esteem that makes one more happy or the other way around; hence the term directionality problem).
-The Third Variable Problem: Something else could possibly be the result of the relationship; something else explains the relationship.
Ā Question to consider: When do we use correlation studies versus experimental studies designs?
-examining the life of one person in-depth (almost like an autobiography except you are trying to figure out about the how and why the person lived the way they did or come to be)
-method invented by Sigmund Freud (my favorite historical psychologists)
Advantages of case studies:
Ā -provides insights into rare behaviors(such as multiple personalities and motivation for behaviours)
Ā -because it is very in depth, provides a rich source of hypothesis or research to do.
-very time consuming (studying one person can be a lot of work)
-not generalizable (just because one person's motive for behaving a certain way does not mean everyone else is the same)
-researcher bias can arise (researcher may pay attention more to specific behaviour and ignore relevant ones; may pay more attention to certain details; may tweak the findings)
-misinterpretion (if you're not very perceptive or knowledgeable yourself and can not reliably translate findings)
-through letters (so person being study mails letter to researcher for a period of time)
-by interviewing a bunch of people who knows the individual (almost like observer reports)
-following the person around with a video camera and record, with sound and image, the actions in his or her everyday life.