IF you do this DT, it counts towards +2 points towards the 15 total Participation points discussed on Syllabus under Attendance Policy – if all instructions below are followed. This will be on Exam 3 in some fashion – this is ALSO going to be involved in your Project Result’s summaries – so critical to Understand!

From the Power Point Slides and Book, one key area that should be know is the “type” of info we learn about our data from the Measures of Central Tendency (mean, median, and mode) vs. Measures of Dispersion (range, and standard deviation). This will be on Exam.  Measures of “Central” Tendency gives us info about the center of our data.  We would prefer to use mean IF we can, but it’s not always possible due to the level of measurement or if there is an extreme case/outlier which would cause the mean to be a lot different than the median and mode. Our job is to determine which MCTs are appropriate to use for any given variable.  Measures of “Dispersion”  how “spread out” our data is.  Range gives us the low and high point, but it’s the SD that tells us how closely respondents answered a given question or were the answers really varied.  A very LOW SD would indicate that the majority answered a question with the same answer while a HIGH SD tells us there was a lot more variation within the responses given.  Example:  Scale of 1 to 5.  IF everyone answered “3” – the Mean would be “3” with the SD=.000 (no variation).  However, we could have just as many who answered “1” as “5” and still have a “3” mean – but the responses are more varied; thus, there would be a higher SD score.  

One area that students often struggle with which affects the exam too is they confuse Measures of Central Tendency (MCT -mean, median, and mode) and Levels of Measurement (Nominal, Ordinal, Interval and Ratio) -it is KEY that you know the difference so that when I ask for MCT OR Levels of Measurement, you know what to actually provide.

1. For EACH Level of Measurement (4 of them), Please give ONE example with asked for information (a to d below) – please answer ALL “a to d” FULLY For ONE level BEFORE moving to the next: 

     a. Write out the variable name, 

     b. Please give ALL attributes/categories – must be a min. 4 of  for all ordinal; and try for at least 4 for nominal if can logically do it (some may only require 2 or 3, and use other for nominal), (remember these can vary depending on what you intend to use for level of measurement – i;.e. how old are you__? is ratio, but how old are you 1. 18 to 24, 25 to 34…… is ordinal)

     c.  Identify if it is N, O, I, or R (level of measurement) – Should be ONE of EACH

     d.  Identify what/which Measure of Central Tendency (MCT) is/are APPROPRIATE for that variable (list ALL that are appropriate, not just the highest one- look at exceptions for ordinal on written PP too, to include please)

*  Please Do NOT – combine Interval and Ratio – please give separate examples
* For ANY Ratio – the responses would be “Exact xxxx recorded” — you can’t possibly list every age, height, weight, etc.
*  Please try to come up with something other than AGE for Ratio
*  Please Do NOT use ANY examples from past Assignments, Book, nor PP (would only allow this for Interval if nothing else can be thought of – but try!)
*  Please Do NOT put Unit of Analysis like Individual, Group, etc., there is no way to know from 1 variable what the Unit of the study would be. 

EXAMPLE: (please do NOT use Gender/Sex) as one of your variables)

Variable name:  Gender     Variable Attributes:  Males, Females, Other   

Level of Measurement:  Nominal    Measure of Central Tendency (MCT): Mode only bc its nominal

PEER POST NOT REQUIRED – you can comment if you’d like, but it’s not Necessary