1.11 Research and Informatics

What is a hypothesis?

A tentative testable answer to a research question

What is a directional or one tailed hypothesis?

A prediction regarding a positive or negative change relationship or difference between two variables in a population

What is a non directional or two tailed hypothesis?

An alternative hypothesis stating a difference between two variables exists without claiming a positive or negative direction

What is a null hypothesis?

A statement describing the expected result if there is no difference between two values being compared stating no significant difference between means

What is an alternative hypothesis?

A statement describing the expected result if there is a difference stating there is a significant difference between means

What does rejecting the null hypothesis mean?

Concluding that values are different by rejecting the claim of no difference when p value is less than the significance level such as p less than 0.05

What does failing to reject the null hypothesis mean?

Concluding there is no evidence that values are different when p value is greater than or equal to the significance level such as p greater than or equal to 0.05

What is a Type 1 error in research?

Rejecting the null hypothesis when it is actually true stating a difference exists when there is none

What is a Type 2 error in research?

Failing to reject the null hypothesis when it is actually false stating no difference exists when there actually is one

Which hypothesis testing error is considered more serious?

Type 1 error is a more serious error than Type 2 error

What is a dependent variable?

The variable being studied in an experiment that changes as a result of changes made to the independent variable

What is an independent variable?

The variable the researcher changes or manipulates in an experiment which is not affected by any other variable

What is a constant variable?

A factor the researcher keeps the same between groups being tested in an experiment

What is a confounding variable?

A factor other than the one being studied associated with both dependent and independent variables that distorts or masks the true effects

What is a Chi square test used for?

Testing a null hypothesis about the relationship between two categorical variables with no order such as Yes or No or blood types

What is a T test used for?

Testing if two means are equal or significantly different using one categorical variable and one quantitative variable with smaller groups

What is a one sample t test?

Checking if the mean of data from one group is significantly different from a known or standard value

What is a two sample t test?

Checking if the means of two independent groups are significantly different from one another

What is a paired t test?

Testing the same single group twice to compare means

What does ANOVA stand for and what is it used for?

Analysis of Variance used to test for differences between three or more population means using at least one categorical and one quantitative variable

What is a Z test used for?

Testing if two means or proportions are equal or significantly different in larger groups when the population standard deviation is known

What is a p value or probability value?

A value helping determine whether observed results are likely to reflect real differences between groups or chance occurrences

What is the standard significance level for p values in research?

A significance level of 0.05 o