WEEK #3 - research methods Flashcards
how many levels of measurement are there ?
4
what are the four levels of measurement ?
- nominal
- original
- interval
- ratio
define nominal data :
- categorial data with no implicit ordering
- cannot be added, subtracted, multiplied or divided
- can be summarized using mode only
define ordinal data :
- categorial data with implicit (or explicit) ordering
- unequal distance between points
- cannot be added, subtracted, multiplied or divided
- can be summarized with median or mode
define interval data :
- continuous (equal distance between points)
- no meaningful zero
- can be added or subtracted
- cannot be multiplied or divided
- can be summarized with mean, median or mode
define ratio data :
- continuous (equal distance between points)
- meaningful zero
- can be added, subtracted, multiplied and divided
- can be summarized with mean, median, or mode
give an example of nominal data :
“25 animals” (10 dogs and 15 cats)
give an example of ordinal data :
“positions in a race : 1st, 2nd, 3rd”
give an example of interval data :
temperature in celcius
give an example of ratio data :
temperature in Calvin
which level of measurement has no meaningful zero ?
interval data
which level of measurement has a meaningful zero ?
ratio data
when might you be able to treat ordinal as interval data ?
- you are aggregating multiple items
- the underlying construct is continuous
- the measurement instrument is reliable
what are the three M’s of central tendency ?
mean, median and mode
what is mean ?
the arithmetic average of the data
what is median ?
the point that divides the data in half and the 50th percentile
what is mode ?
the most frequently occurring value
which central tendency is “ total all the results and divide the number of units or “n” of the sample” ?
mean
which central tendency is “the exact middle score in a data-set and list all scores in numerical order, and then locate the score in the centre of the sample”
median
does median ignores the outliers compared to a average ?
yes ignores the outliers
which central tendency is “the most repeated score in the set of results, 15 is the most repeated score and is labeled the mode and if you have a “tie” for “most repeated score”, you will have more than one mode”
mode
in regards to normality and central tendency, what does it mean if the distribution is normal ?
the mean, median and mode are all equal (bell-shaped)
what are the three factors of dispersion ?
- range
- standard deviation
- coefficient of variation
why do we use range :
good for an intuitive description of minimum and maximum values in a data set