inferential statistics - chemistry · inferential statistics cheat sheet review the cheat sheet and...

Inferential StatisticsEducating students on when to

use inferential statistics

Inferential Statistics

Link: http://www.wolframalpha.com/

examples/Statistics.html

The Goal: Moving beyond the data to make an effective analysis.

Note: Statistics are numerical processes that add depth to quantitative data sets.

Note: Qualitative sets provide value through rich description, but can be coded numerically to then use statistical methods.

We will use Star Wars to learn about Inferential Statistics.

3 Levels of Descriptive Statistics

1. Padawan: Hypothesis Basics

2. Jedi Knight: Sampling Distribution and Estimation

3. Jedi Master: Hypothesis Testing in Practice Don’t give into the hate of statistics.

Don’t give in to the Dark Side.

Use the force. Make your data depthful, you will.

Padawan Level: Hypothesis Testing

Hypothesis Testing: The process of testing a predicted relationship or hypothesis by making observations then comparing the observed

facts with the hypothesis or predicted relationship(Research Methods, 413)

Hypothesis Basics● A hypothesis is all about establishing relationships

amongst studied variables and application

If _______________________________ then _______________________________

● The job of the researcher is to attempt to prove the relationship is valid BUT… for this paper, it is okay if the relationship cannot be established. No relationship is also information that your BOK may need.

Hypothesis Basics● Null Hypothesis: Typically, the null hypothesis rejects any

relationships established in the original hypothesis.● Example… ;)

○ RQ: Can a teacher cause an entire class to fall asleep due to a statistics lecture?

○ Null: Forcing students to listen to a statistics lecture will show no change in their classroom sleep patterns.

Hypothesis Basics● Alternative hypothesis: The logical opposite of the null

hypothesis● Example….

○ Null: Forcing students to listen to a statistics lecture will show no change in their classroom sleep patterns.

○ Alternate hypothesis: Forcing students to listen to a statistics lecture will show change in their classroom sleep patterns.

Hypothesis Testing● Your hope by the end of your research:

○ Mathematically reject the null hypothesis PROVING that the relationship of study does actually connect…

AGAIN

● Your paper is not crushed if you cannot reject the null (maybe your spirit but not your paper). This is information that your Body of Knowledge needs!

Activity: If/Then T-ChartCreate a T-Chart in your notes

● Start by documenting your true alternate hypotheses.● After exhausting that list, start documenting all of the POTENTIAL “hidden”

relationships that could arise in your data set. ● Your list should be at least 20 items long.

○ Situational Issues○ Demographics○ Cultural Norms○ Method Error

Moving to Level 2...

Jedi Knight Level: Sampling Distributions and Estimation

Making your data connect to a larger population.

Sampling Distribution● Sample: Set of cases

selected from a population● Population: Full group to

which one wants to generalize

● Parameter: Numerical characteristic of a population

Sampling Types:● Randomized Sampling● Targeted Sampling● Convenience Sampling

Side Note: Case Study omits sampling statistics

Sampling Distribution● Sampling Distribution:

Randomized portion of a given group (population)

● This would be used for a large data set to save the time and energy of the researcher.

● Example: You surveyed 1000 people and only study 10% of those responses.

Most of the studies in AP Research will not use Sampling Distribution.

Populations are too small to segment.

Estimation● Estimation: Focuses on

obtaining estimates of the values of population parameters.

● Point Estimation: Use the value of a sample as one’s estimate of the value of a population parameter.

● Confidence Interval: Range of accuracy regarding a particular population parameter.

*Anyone wishing to apply their data to a larger population must attempt Estimation.

Jedi Master Level: Hypothesis Testing in Practice

Inferential Statistics Cheat SheetReview the cheat sheet and try to find

the design that is close to your research.

Don’t forget: Talk with an expert adviser for more support about your own decisions regarding the use of

statistics for your paper.

Congratulations! Pat on back, you deserve!

Tell me more about how to organize your data...