Experimental Method
Experimental method is the one most used in the scientific research of behavior.
The parts to this method are:
- A clear statement of the problem to be studied.
- Operational definitions, which are defining terms by means of how they are being measured, are added.
- The hypothesis, otherwise known as an educated guess, sets the direction of the research.
The sample, which is who we are studying, is divided into a control group, a group that is not being manipulated and is used to set the standard or comparison, and the experimental group, the group that receives the independent variable.
Dependent Variable
Independent Variable
Confounding Variable
A conclusion is then reached.
This method of study is good because it is the only method that allows us to do a cause and effect.
Let's look at an experiment on whether or not music affects concentration.
What would the different parts of the experimental method be?
The operational definition
Your hypothesis
The independent variable
The dependent variable
Confounding variables
Natural Observation
The second method is natural observation.
This method does exactly what its name
implies.
You watch the behavior in a natural
environment.
This can be done in one of two ways.
- Overt observation - the observer can be seen
- Covert observation - the observer cannot be seen
An example: You want to see who is more aggressive at recess, 3rd grade girls, or 3rd grade boys.
Overtly, you could walk around and observe them and let them know they are being observed.
The problem with this is that their behavior could change.
You could also observe them while hidden behind something and observe the behavior.
But you may not be in the right place at the right time.
Correlational Studies
The third research method is correlation.
Correlational studies are used to investigate relationships between variables. Correlation is determined by a mathematic equation resulting in a number called the correlation coefficient.
The correlation coefficient is a measure of strength and can range
from -1.00 to +1.00.
The closer the correlation coefficient is to either negative or positive one, the stronger the relationship between the variables.
There are three possible results of a correlational study: a positive correlation, a negative correlation, and no correlation.
Positive Correlation: Both variables increase or decrease at the same time.
Negative Correlation: Indicates that as the amount of one variable increases, the other decreases (and vice versa).
No Correlation: A correlation coefficient of 0 indicates no correlation.
The most important thing to remember is that correlational studies only show relationships between variables not the cause.
An example of a negative correlation would be looking at data on the amount of time students spend playing Nintendo games and test results.
As students spend more time playing Nintendo games, test grades should go down. This is a negative correlation because as one set of data increases, the other set decreases.
An example of a zero correlation would be looking at data for how long your hair is and how well you perform on tests.
There is no comparison. Therefore it is a zero correlation and you should not try to find any relationship in the data.
Survey/Interview Method
The fourth research method is the survey/interview method.
It is very simple because if you want to know about behavior, you ask people about their behavior. As easy as it seems, there are two important things you have to take into consideration.
- You must get a random sample.
- You must consider biasing.
The good points of the survey interview method are that it seems quick and easy.
The downside of the survey interview method is lack of random samples and biasing.
Statistics
Statistics are the mathematical tools that help us show the results of our research.
The most often used statistics are the measures of central tendency - or the mean, median and mode.
They answer the question in psychology of how behavior compares to that of others, and to some extent defines the normal of behavior.
Psychologists use statistics to organize, summarize, and interpret the information they collect.
These three measures are used to define central tendency.
Look at these five test scores: 64, 93,64,72,85.
Mean is the average. To find the mean, add up the five test scores and divide by five. Means can be distorted by extreme scores.
64+93+64+72+85=378 /5= 75.6 is the mean of our scores above.
Median is the middle score. To find the median score, rank each of them from the lowest to the highest and find the one in the middle, or the number that would be in the middle of two scores if there is an even amount. 64+64+72+85+93 = 72 is the median.
Mode is the most frequent score. In a number of scores, which one is repeated most often? You may have one or two modes within a set of scores, or you may have no mode at all. 64+64+72+85+93= 64 is the mode.
Statistical significance
Psychologists usually consider a result to be statistically significant if such a result occurs just by chance 5 or fewer times out of every 100 times a study is done.
If it's unlikely that the difference was due to chance, then the observed difference could be considered statistically significant. However, statistical significance alone does not make a finding important.
Statistical significance simply means that a result is probably not due to chance.
Longitudinal Studies
Longitudinal studies research is a type of research that involves studying the same group of individuals over an extended period of time.
The benefit of this type of research is that it allows researchers to look at changes over time.
However, they do require enormous amounts of time and tend to be very expensive.
Cross-sectional research
Cross-sectional research is a research method often used in developmental psychology.
This type of study looks at different groups of people who differ in the variable of interest, but share other characteristics such as socioeconomic status, educational background, and ethnicity.
For example, researchers might select groups of people who are remarkably similar in most areas, but differ only in age.
By doing this, any differences between groups can presumably be attributed to age differences rather than to other variables.
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