Summerizing Data

Question 1

Two major types of data

Answer 1

Quantitative
- numerical data that does NOT describe a cause and effect or comparison

Qualitative
- non-numerical data that is described in words or letters and often presents a comparison/ratio

Question 2

5 scales of data ranked in order of most to least information content

Answer 2

Continuous ratio

• number scale that has a true zero as a possible answer
• highest information content

Continuous interval
- number scale (such as temp) with NON-true zero

Ordinal data

• scales from 1: whatever
• ex: on a scale from 1-6 what is the pain?

Binary data
- yes or no and direct percentages

Nominal data

• just a value w/ no correlation
• a name/ a blood type/ a country/ etc.
• lowest information content

Question 3

Continuous data explained

Answer 3

Generally described w/ an estimate of the shape and center of the distribution and variability of the data
- always produces an average however the average value alone is not enough

Question 4

Three common estimates of the typical patient (estimates of the average)

Answer 4

1) mean
2) median
3) mode

Question 5

Is the mean the most important statistic?

Answer 5

No not always, it depends on the distribution of the data (or shape of the data)
- can use for symmetric data curves

Question 6

Right or left skewed shaped histogram uses what estimate of center and variability

Answer 6

Median and interquartile range

In right skewed data, the mean is generally larger than the median and the mode is less than the median
- mean > median > mode

In left skewed data, the mode is generally larger than the median and the mean is less than the median
- mode > median > mean

• note that the data is named for where the tail is!*

Question 7

Bimodal shaped histogram uses what estimate of center and variability

Answer 7

Mode and interquartile range

Question 8

Symmetrical shaped histogram uses what estimate of center and variability

Answer 8

Mean and standard deviation

Question 9

Standard deviation

Answer 9

Is the average deviation from the mean

Question 10

Normally distributed symmetric shaped statistics information

Answer 10

1) is symmetric
2) centered at the mean

3) 3 standard deviations will encompass 99.7% of the data
- 1 deviation = 68%
- 2 deviations = 95%
- 3 deviations = 99.7 %

4) anything not in the 3 standard deviations are outliers

Question 11

What do you use to report ordinal (scaled) data to patients

Answer 11

Same as the continuous rotation (based off the shape of the data)

However if there are not enough unique levels (usually <5 ) just use median and IQR

Question 12

What is variance?

Answer 12

Standard deviation squared

- used to calculate data but is almost never reported