Assignment: random sample participants.
Assignment: random sample participants.
Assignment: random sample participants.
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Assignment: Describe how the group will obtain a random sample of participants.
a. The course term paper is an in-depth research paper on a pre-approved topic in the area of Psychology. Your sources are to be only from the professional literature (journals) and professional books. Cite all sources in the body of the paper in APA citation style, with an APA style References page at the end of paper containing a minimum of three to five professional journal references in addition to other sources. Do not quote from your source, but simply put in your own words and cite the reference. While quality of content and writing is most important, the paper should be a minimum of between 8 to 10 pages (double spaced). Use Arial or New Times Roman 12 point fonts only, double space between lines, and with 1 inch margin on all 4 sides. This is an opportunity for you to dig into a topic area that interests you and really learn what is known (and not) about it.
I will need two variables with at least five sets of data. between these two variables: time spent playing video games and aggression.
Then in 500-750 words, do the following:
Describe how the group will obtain a random sample of participants.
Assume the study produces a correlation of .56 between the variables. Analyze three possible causal reasons for the relationship.
Population vs Sample
The population includes all objects of interest whereas the sample is only a portion of the population. Parameters are associated with populations and statistics with samples. Parameters are usually denoted using Greek letters (mu, sigma) while statistics are usually denoted using Roman letters (x, s).
There are several reasons why we dont work with populations. They are usually large, and it is often impossible to get data for every object were studying. Sampling does not usually occur without cost, and the more items surveyed, the larger the cost.
We compute statistics, and use them to estimate parameters. The computation is the first part of the statistics course (Descriptive Statistics) and the estimation is the second part (Inferential Statistics)
Discrete vs Continuous
Discrete variables are usually obtained by counting. There are a finite or countable number of choices available with discrete data. You cant have 2.63 people in the room.
Continuous variables are usually obtained by measuring. Length, weight, and time are all examples of continous variables. Since continuous variables are real numbers, we usually round them. This implies a boundary depending on the number of decimal places. For example: 64 is really anything 63.5 <= x < 64.5. Likewise, if there are two decimal places, then 64.03 is really anything 63.025 <= x < 63.035. Boundaries always have one more decimal place than the data and end in a 5.
Levels of Measurement
There are four levels of measurement: Nominal, Ordinal, Interval, and Ratio. These go from lowest level to highest level. Data is classified according to the highest level which it fits. Each additional level adds something the previous level didnt have.
Nominal is the lowest level. Only names are meaningful here.
Ordinal adds an order to the names.
Interval adds meaningful differences
Ratio adds a zero so that ratios are meaningful.
Types of Sampling
There are five types of sampling: Random, Systematic, Convenience, Cluster, and Stratified.
Random sampling is analogous to putting everyones name into a hat and drawing out several names. Each element in the population has an equal chance of occuring. While this is the preferred way of sampling, it is often difficult to do. It requires that a complete list of every element in the population be obtained. Computer generated lists are often used with random sampling. You can using the TI82 calculator.
Systematic sampling is easier to do than random sampling. In systematic sampling, the list of elements is counted off. That is, every kth element is taken. This is similar to lining everyone up and numbering off 1,2,3,4; 1,2,3,4; etc. When done numbering, all people numbered 4 would be used.
Convenience sampling is very easy to do, but its probably the worst technique to use. In convenience sampling, readily available data is used. That is, the first people the surveyor runs into.
Cluster sampling is accomplished by dividing the population into groups usually geographically. These groups are called clusters or blocks. The clusters are randomly selected, and each element in the selected clusters are used.
Stratified sampling also divides the population into groups called strata. However, this time it is by some characteristic, not geographically. For instance, the population might be separated into males and females. A sample is taken from each of these strata using either random, systematic, or convenience sampling.
