importance of statistics in scientific...

International Science and Engineering FairMay 10, 2010

Thoughts ExamplesExample 1 Q & A

Importance of Statistics in Scientific Research

Christopher J. Malone, PhDWinona State University, Winona, MNEmail: cmalone@winona.edu

Thoughts ExamplesExample 1 Q & AExample 1

The Hypothesis

Oops, backwards

The Hypothesis

ForceHigh School Project

The Hypothesis

ForceTheory

High School Project

The Experiment

Forcemass speed

The Experiment

160043604410

The Experiment

43604410

160043604410 *

Slush is most

dangerous

The Experiment

43604410

160043604410 *

Slush is most

dangerousRight?

The Experiment

43604410

160043604410*

15904390 * 4380

2nd Trial

The Experiment

43604410

160043604410*

15904390 * 4380

2nd Trial

Yea, but

HollywoodVersion

436044104410*

Measurements

Thoughts

› Measurement details should be in research plan › What are you going to measure?› How are you going to measure?

› Measurement issues go beyond identification of independent and dependent variables

› Outcomes must be measurablee.g. “I will identify the day the plant wilts” is not

precise; carefully measuring soil moisture over time is much better

Measurements

Thoughts

› Numerical measurements are generally better than categorical measurements; however, avoid changing data types

Categorical Now, numerical

Measurements

Thoughts

› Numerical measurements are generally better than categorical measurements; however, avoid changing data types

› Why? Averages, Standard Deviations, Correlations, etc.

Categorical Now, numerical

Measurements

Thoughts

› Comparing Averages…

Averages0.670.50

Measurements

Thoughts

› Comparing Averages…

Averages0.670.50

0.000.50

Measurements

Thoughts

› Measurement issues/concerns are often overlooked› The necessity of precision in measurements cannot be

overstated

Measurements

Thoughts

› Measurement issues/concerns are often overlooked› The necessity of precision in measurements cannot be

overstated

Replication

Thoughts

› Generally speaking, more is better› May be necessary to balance replication and precision

Replication

Thoughts

› How good is my shot?

Replication

Thoughts

Replication

Thoughts

Replication

Thoughts

› Replication allows us to estimate the error due to variables that are not under our control (i.e. noise)

Replication

Thoughts

› Which in turn allows us to measure and possibly attribute an observed outcome to the variables that areunder our control (i.e. effect)

Replication

Thoughts

› Which in turn allows us to measure and possibly attribute an observed outcome to the variables that areunder our control (i.e. effect)

Summaries and Displays

Thoughts

› Usually inappropriate to display raw data, especially for high school projects

Thoughts

› Bar charts should only be used for tallys, not for numerical measurements (including averages)

Thoughts

› Bar charts should only be used for tally’s, not for numerical measurements (including averages)

Thoughts

› Bar charts should only be used for tally’s, not for numerical measurements (including averages)

› Bring back the dot plots! › Simple to construct and easy to read› Stack them to compare groups

Thoughts

› Bring back the dot plots!

Thoughts

Adding Averages, v 1 Adding Averages, v 2

Thoughts

› Generally speaking…› Excel is less than optimal for constructing displays› Numerical data require numerical data displays

› Compute change for paired measurements

Thoughts

› Generally speaking…› Excel is less than optimal for constructing displays› Numerical data require displays for numerical data

› Compute change for paired measurements

Thoughts

› Compute change for paired measurements› % change may be necessary at times

› Scatter plots tend to be under utilized

Thoughts

› Compute change for paired measurements› % change may be necessary at times

› Scatter plots tend to be under utilized

Your summaries and displays should support your story.

Thoughts

160043604410

The Statistical Chapter of your Story

Thoughts

› These elements will give statistics an opportunity to help tell your story› Good experimental design techniques› The collection of precise and error free

measurements› The use of appropriate statistical methods› Interpretations that are meaningful and given within

context

Thoughts

› Borrow ideas and concepts from others › e. g. Marketing› e. g. What are the important elements of an

effective persuasive speech? -Learn from Jack Franchetti @ 10:00AM tomorrow…

Thoughts

› Borrow ideas and concepts from others › e. g. Marketing› e. g. What are the important elements of an

effective persuasive speech? -Learn from Jack Franchetti @ 10:00AM tomorrow…

› In the end, your story may be different than your original hypothesis.

› Many of the young scientists here are not presenting their original hypothesis.

› This is indeed the essence of the scientific method!

› Compliments of Wendy Greenberg, Biology Department, Bemidji State University

› Set-up: 1. Play game 5 times with sound,

then 5 times without sound2. Measurement: Score3. Issues???

Examples

Example #1 (Video Games and Sound)

› Compliments of Wendy Greenberg, Biology Department Bemidji State University

› Set-up: 1. Play game 5 times with sound,

then 5 times without sound2. Measurement: Score3. Issues???

Note: Student recognized issue of potential improvement due to learning, but his solution was to switch the order!

Examples

Example #1 (Video Games and Sound)

Thoughts ExamplesExample 1 Q & AExamples

Example #2 (Influencing the color of a flower)› My hypothesis: Does colored water change the color of a

flower?

› Set-up: 1. What should I measure?2. The type of flower is irrelevant to me, but I will use a

rose and tulip for my experiment. 3. Do I need a control? Why or why not?4. I have room for 16 planting pots in my lab.

Example #2 (Influencing the color of a flower)› Sketching an appropriate randomization plan

Example #2 (Influencing the color of a flower)› The Data

Example #2 (Influencing the color of a flower)› The averages

Thoughts ExamplesExample 1 Q & AQ & A

Q & A Session

Thoughts ExamplesExample 1 Q & AQ & A

Thank you!

Chris MaloneWinona State University

Email: cmalone@winona.edu

importance of statistics in scientific...

Documents

sequence alignments chi-cheng lin, ph.d. associate professor...

importance of statistics in scientific research final...

course1.winona.educourse1.winona.edu/ssegal/molecular course...

summer bioinformatics workshop 2008 chi-cheng lin, ph.d.,...

the escalating importance ofthe escalating importance of...

week 8-bioinformatics/proteomics -...

chapter 6 linkage analysis and mapping three point...

northern illinois university march 2009 susan hatfield...

importance importance dudduudu greffage de …

central dogma of genetics - california state university...

christopher malone (cmalone@winona) tisha hooks...

immunity to bacterial infections bacterial...

virtual pc technical overview 2007 -...

course1.winona.educourse1.winona.edu/cmalone/stat360/notes/handout17.docx ·...

youngstown state university september 2011 susan hatfield...

2012 joint statistical meetings purpose balance...

the basal apparatus determines: • the startpoint for...

instructor: colleen malone office hours: by appointment...

involving undergraduates in statistical...

crowd size estimation (2) - technology - winona...