unit 1 stats

population

response of all _

• an entire group

sample

response of # __

• part of a population

population

response of all _

• an entire group

sample

response of # __

• part of a population

data

% of would, while % would not

population parameter

numerical description of all of a population

• senior class score

sample statistic

numerical description of part of a population

• 1,000 US adults

qualitative

attributes and labels

• hair color, phone numbers, zip codes

quantitative

measurements and counts

• scores, GPAs, weight, height

nominal

categorized qualitative data only (not arranged in a meaningful order)

• labels of movies, phone numbers, allergies

ordinal

qualitative or quantitative data in order/ranked

• top five lists, teams, pain level

interval

ordered with meaningful differences, can go below 0

• years, temperature,

ratio

ordered with meaningful differences, cannot go below 0

• salary, heart rate, weight

observational

observes and measures characteristics, nothing is changed

• no treatment being recieved by patients

experiment

treatment and control group

• treatment is applied

simple random sample

every person has the same chance of being selected

• random digit dialing
• bias: not everyone has the form of media the researcher uses

stratified

a few members from each group are sampled

• students divided by class and a few are used
• bias: one class may be a majority/underrepresentation

cluster

every member from a few groups are sampled

• selecting every household in a district from some grids
• bias: selected groups may not represent the whole pop.

systematic

every member is assigned a number and randomly selected

• stopping every fourth person and interviewing them
• bias: proximity and type of location samples are leaving

convenience

samples are easy to get

• interviewing friends
• bias: underrepresentation, biased opinions