Stats 300

what are the three steps of conducting a statistical study?

(PAC) Prepare, Analyze, Conclude

Define interval

(Quant) no natural 0 point (temp/calendar)

define Ratio

(quant) has a natural 0 point. example: price of txtbook

what is a parameter?

A numerical summary of a population. ex: # of miles driven (P for P)

What is statistic?

A numerical summary of a sample from the population (S for S)

what is continuous data?

Continuous data are not restricted to defined separate values( NO GAPS) example would be foot size (6.1,6.2,6.3) mph (42.566mph) can be in between.

what are the 3 types of observational studies? which ones are past. present and future?

Cross sectional( present) retrospective (past) prospective (future)

what is discrete data?

Discrete data can only take particular values. (Examples include shoe size, 6.5,6,7,7.5, Has gaps)

Define double-blind study

Identify of interventions unknown to BOTH subject and investigator.

Define nominal

Organizes data into mutually exclusive categories that have no rank, order, or value ex. male v female (QUAL)

Type of car a person drives, QUAN OR QUAL?

Qualitative

Distance a car travels on one tank of gas, QUAN or QUANT? DISCRETE OR CONTINUOUS)

Quant, continuous because it could be lile 12.3 miles

define random sampling

Sampling methodology where each item in the population has the same probability of being selected. (ex: drawing from a hat)

Define inferential statistics

Used to make inferences or generalizations about the ENTIRE POPULATION based on data taken from a sample of that population.

what is a census?

a collection of data from EVERY member of the population

What is data?

a collection of facts from which conclusions may be drawn (measurements, counts, surveys etc)

what is a population?

a large # of people (ALL)

Define experiment

a set of controlled observations that test the hypothesis (apply some treatment and then observe)

what is a sample?

a small # from the population (SOME)

define observational study

an experiment in which the observer collects data over time WITHOUT interacting with the area of study

Define convenience sampling

asking people wherever is convenient (ex. grocery store)

What is qualitative/categorical data?

can put in categories of names or labels (ex: hair color, height etc)

define non sampling error

data was collected or recorded incorrectly

what are the two branches of statistics?

descriptive and inferential

what are the two types of quantitative data?

discrete and continuous

Define cluster sampling

diving the population into sections, selecting some of the selections, and then choosing ALL from the selections chosen (example: choosing 5/50 states, and then sampling ALL from the five states)

define confounding

error that occurs when the effects of two variables in an experiment cannot be separated, resulting in a confused interpretation of the results

Define blinding

is when the subject doesnt know if he/she is recieving the placebo effect( thinks its working/helping)

suppose a sample of 250 flc students is obtained, and from this sample we find that 83.5% have a job. is this a parameter or statistic? and is it a sample or population?

it is a sample because it's only SOME, and it is a statistic because it's a piece of the population.

suppose the percentage of all students on your campus who have a job is 84.9%. is this a population or a sample? and is it a parameter or a statistic?

it's a population, also parameter because it says ALL

what are the 4 levels of measurement?

nominal, ordinal, interval, ratio

what is quantitative data?

numbers obtained by counting or measuring

define voluntary response

only people who are INTERESTED will VOLUNTEER, and often have bias which is bad.

define Self-interest study

only people who will BENEFIT from the results( a reward or whatever)

Define ordinal

ordered categories (bad,good, excellent) (QUAL)

define simple random

picking groups randomly at a time (like groups of five)

# of times your internet goes down quan/qual? discrete/continuous?

quantitative, discrete. cant go down 1.2 times. gotta be 1 or 2

define systematic sample

randomly selecting from the starting point and then every kTH time (ex: every 3 apples)

Define descriptive statistics

summarizes and describes aspects of a data set

define sampling error

the natural discrepancy, or amount of error, between a sample statistic and its corresponding population parameter

Define stratified sampling

the researcher divides the population into separate groups,. Then some people are drawn from each group. (example: choosing 5/50 states and then sampling SOME from each state)

What is statistics?

the science of collecting, organizing, analyzing, and interpreting data in order to make decisions

What is one goal of statistics?

to learn about a larger group by examining a sample of its members