# 3.1 intro to biostatisitics Flashcards

The null hypothesis is either accepted or rejected based on what?

Statistical analysis

What does the null hypothesis state?

Research perspective which states there will be no true difference between groups being compared

What 3 primary levels for variables?

Nominal data, Ordinal data, and intervel/ratio data

What are the 3 key attributes of data measurement?

Order/Magnitude. Consistency of scale/equal distances. Rational absolute zero.

What is an ex of nominal?

Labeled variables without quantitative characteristics. ex. Lawyer, truck driver.

what is an ex of ordinal?

Theres order and magnitude. ex. Pain scale

What is an ex of interval/ratio?

ex living siblings (#) and personal age (in years)

Define mode

most frequent

Define median

middle number

Define mean

average number

Define variance

Average of the squared differences in each individual measurement value x and the groups X-

Define Standard deviation

Square root of variance value.

What are parametric tests?

Stat tests useful for normally distributed data

Is the curve Negative or Positive skewed.

Is the curve Negative or Positive skewed?

If the data is skewed what cant it be?

Interval

What is kurtosis?

Tells how peaked a value is

If theres more cluster in a graph, what type of Kurtosis is it?

Positive

If theres less cluster in a graph, what type of Kurtosis is it?

Negative

What are the 4 key questions to selecting the correct statistical test?

- What data level is being recorded. 2. What type of comparison/assessment is desired. 3. How many groups are being compared? 4. Is the data independent or related (paired)?

What are the two sub catagory questions to ask for What Data LEVEL is being recorded?

- Does the data have order/Magnititude? 2. Does the data have an equal distance?

What are the 4 catagory questions to ask for What type of Comparison Assessment is desired?

- Correlation. 2. Regression. 3. Surival 4. Group comparison

What does Correlation (r) do?

Provides a quantitative measure of the stength and direction of a relationship between variables.

What is partial correlation?

A correlation that controls for confounding variables