Lesson 1: Introduction to Statistics

Question 1

whats the point of statistics?

Answer 1

• the consequences of mathematical innumeracy are not usually as obvious as illiteracy
• lack of numerical perspective
• misunderstanding of probability

Question 2

why do we study statistics?

Answer 2

• in order to understand a scientific discipline it is necessary to know the procedures for evaluating scientific evidence

Question 3

when many groups and individuals attempt to influence your behaviours with statistical arguments, what enables you to evaluate arguments in a responsible manner?

Answer 3

knowledge of statistics

Question 4

what is statistics?

Answer 4

the science of the collection, organization, analysis, and interpretation of DATA
- is a set of procedures and principles for collecting and organizing data and analyzing information in order to help people make decisions when faced with uncertainty

• “how should we collect data? what variables?”
• different groups of statistics may be chosen differently based on who is pulling the information

Question 5

what is the big picture of statistics?

Answer 5

• goal of statistics is to take data from a sample and make conclusions about the population
• depends on if it is a representative sample (can you compare the shoe size of one class to the rest of the world)

Question 6

when something is statistically significant, does this mean it is important?

Answer 6

no

Question 7

data is not information until it is?

Answer 7

interpreted

Question 8

how do we discover knowledge?

**

Answer 8

1, ask right question (must be answerable)
2. collecting useful data, which includes deciding how much is needed
3. summarizing and analyzing data, which the goal of answering the questions
4. making decisions and generalizations based on the observed data
5. turning the data and subsequent decisions into new knowledge

Question 9

what are the two types of statistics?

Answer 9

1. descriptive statistics
2. inferential statistics

Question 10

what is descriptive statistics?

Answer 10

• “this is what people in this room do”
• organize, describe and summarize a small dataset
• results obtained represents the entire dataset
• often used when researchers begin a new area of investigation

Question 11

what is inferential stats?

Answer 11

” can we generalize this to the broader population”

• designing experiment and generalize to broader population
• can be used to determine cause and effect relationships, test hypothesis and make predictions

Question 12

what number is used typically as a differentiater?

Answer 12

30 samples (average of group usually looks like the average of a population)

Question 13

what is a population?

Answer 13

• all of the objects that researchers want to describe or make inferences about
• characteristic of population = “parameter”

Question 14

what is a sample?

Answer 14

a subgroup of population that researcher believes represents the population
- a group of specific size (n=) is selected and measured

• characteristic of sample = “statistic”

Question 15

what is the best samples for experiments?

Answer 15

those which are selected randomly

Question 16

what does random sample mean?

Answer 16

sample is unbiased

Question 17

how do we achieve a random sample?

Answer 17

every element of the population must be equally likely to be selected to sample group (selection of one element does not affect the possibility of other elements being selected)

Question 18

what is a variable?

Answer 18

• characteristic of a person, object or phenomenon that is amenable to change and is measurable
• any observable/measurable properly of organisms, objects or events

Question 19

what are the two types of variables?

Answer 19

1. Quantitative (numerical)
2. Qualitative (Categorical)

Question 20

what is the difference between continuous vs discrete quantitative variables?

Answer 20

• continuous: can theoretically take on any value within a given range
• discrete: can only take on certain values (eg. number of children in a family)

Question 21

what are the types of qualitative variables?

Answer 21

1, binary (two categories) (eg. dead/alive)
2. more than two categories (eg. hair colour)

Question 22

what are the four levels of measurement in the classification of data?

Answer 22

1. nominal (name/order doesn’t matter/category)
2. ordinal (order matters/category/data is ranked) (small medium large)
3. interval (intervals between categories is fixed) (1, 2, 3, 4 all have the same distance between eachother) (arbitiary 0 point like temperature, or time)
4. ratio (Kalvin temperature (true zero, indicated an absence of the variable))

• first two is qualitative
• last two is quantitative
• more information conveyed as one moves from A to D

Question 23

what is a dependent variable?

Answer 23

• the variable of primary interest (measured)
• a variable whose changes we wish to study; a response variable
• the variable designed to measure the effect of the variation of the independent variable

Question 24

what is an independent variable?

Answer 24

• a variable we believe affects the measurement obtained on the dependent variable (it is manipulated)
• a variable whose effects on the dependent variable we wish to study
• the variable that the researcher changes within a defined range, to study the effect on the dependent variable

Question 25

do we need to be careful when using the word "cause"?

Answer 25

yes. smoking does not CAUSE cancer, only influences

Question 26

statistical methods are the researchers tools to?

Answer 26

1. assist in describing data 2. in making inferences or generalizations from experimental data (sample) to larger groups (population) 3. in studying causal relationship