Chapter 1 Flashcards
What does statistics study?
Science of using data to study characteristics of a population
pg. 3
What is Descriptive Statistics?
Organizing, summarizing, presenting and analyzing the data
pg. 4
What is Inferential Statistics?
Interpreting the data and drawing conclusions based on the data.
Infer=to arrive
pg. 4
What is a population?
All the people or things being studied
pg. 4
What is a sample?
Some of the people or things being studied
pg. 4
What does studying a sample do?
Allows you to estimate or infer the properties of the population
pg. 5
What is a representative sample?
has characteristics that are similar to the population
good
pg. 6
What is a non-representative sample?
has characteristics that are NOT similar to the population
bad
pg. 6
What is a random sample?
Every population member has an equal chance of being selected
good/representative
pg. 8
What is a simple random sample?
Were members of the population are selected at random and individually
best type of sample
pg. 8
What is a cluster sample?
The population is divided into clusters(groups) and then clusters are randomly selected and all members of that cluster are sampled
pg. 9
What is stratified sampling?
The population is divided into at least 2 different subgroups. Then we draw a sample of some of the members from each subgroup
pg. 9
What is systematic sampling?
We select every kth(such as each 5th) member of the population
can be problematic
pg. 10
What is convenience sampling?
When people conducting the study just use a sample that is convenient for them
generally yield poor results
pg. 11
What is a voluntary response sample?
When a sample is made from members of the population who choose for themselves whether or not to be in the sample
Never acceptable and have poor results
pg. 11
What about an election?
In an election people choose whether or not to vote however voters are the population not the sample
pg. 13
What is bias and why might it lead to poor data?
If the people conducting or paying for a study have an interest in getting certain results, they might unethically collect or use data only from places that give them results they want.
pg. 14
What is a reported result why might it lead to poor data?
What people say about themselves (self-reported) people can be inaccurate about themselves, especially when asked about sensitive topics results should be measured instead
pg. 15
What is a small sample and why might it lead to poor data?
Too few of a sample to skew results
pg. 15
What are confounding variables and why might it lead to poor data?
When multiple variables are involved and it’s hard to tell which variable causes which effect
pg. 16
What are loaded questions/the order of the questions and why might it lead to poor data?
Sometimes the way a question is written or the order they are given can have an effect on how people answer e.g. more than or less than can be confusing/subjunctive
pg. 16
What is non-responses and why might it lead to poor data?
When people asked to participate in a study refuse to respond needed to be counted to keep the data from being skewed
pg. 17
What is missing data and why might it lead to poor data?
When entire segments of the population are left out, depending on the study it could have a significant effect on the data
pg. 17
What is statistical significance?
When the evidence supports the findings
pg. 18
What is practical significance?
When the effect is large enough to be meaningful in the real world
pg. 18
What is a parameter?
Numerical results describing some characteristic of a population
(p=p) actual result for the population
pg. 18
What is a statistic?
Numerical results describing some characteristic of a sample
(s=s) estimate of the population
pg. 18
What is discrete data?
When possible result values are at set intervals
e.g. shoe sizes
pg. 20
What is continuous data?
When possible results cover any decimal within a range of values
e.g. length and time
pg. 20
what is quantitative data?
Consists of numbers that represent counts or measurements.
quaNtitative=Number
pg. 22
What is qualitative data?
Consist of names or labels that are NOT numbers that represent counts or measurements
quaLitative=Label
pg. 22
What is an observational study?
When we observe and measure specific characteristics but do NOT attempt to modify the subjects
pg. 24
What is an experiment?
When treatment is applied and the effects on the subject are studied
pg. 24
What is the difference between the control group and experimental group?
The control group gets the placebo
The experimental group gets the actual treatment
pg. 25
What is a blind experiment?
When subjects are not told if they are receiving the actual treatment or the placebo
This has to be done for a placebo to work
pg. 26
What is a double blind experiment?
When subjects and the doctors/professionals are not told who is receiving the actual treatment or the placebo
Prevents bias and is the best study we have
pg. 26
What is a proportion?
A percent in decimal form
proportion=# in the category/total
pg. 26
