on being a statistician: normality not required presented to mr. kunkle’s statistics class by...
TRANSCRIPT
On Being a Statistician:Normality not Required
Presented to Mr. Kunkle’s Statistics Class
By Robert Capen
About me
I have a Ph.D. in Statistics from the University of Florida
I have worked in industry since 1991I have been at Merck since 1995
What got me interested in Statistics?
I really liked the fact that statistics was an applied science It wasn’t just mathematical theory but also
required creative thinking, critical evaluation and good people/listening skills
I am a skeptic at heart and statistics gave me a valuable set of tools to evaluate the conclusions others drew from the data they collected or analyses they performed
What careers are out there for Statisticians?
PharmaceuticalFinancialInsuranceIndustrialAcademiaGovernmentConsulting
What careers are out there for Statisticians?
Statistician: Navarro Research and Engineering Navarro Research and Engineering, Inc. is a premier
contractor for the Department of Energy (DOE) and the National Nuclear Security Administration
Pricing Statistician: Grainger Position Description: Responsible for providing input to the
development and execution of Grainger’s price delivery strategy across GIS Brand segments.
Intern-Statistician: Flextronics International Headquartered in Singapore, Flextronics is a leading
Electronics Manufacturing Services (EMS) provider focused on delivering complete design, engineering and manufacturing services to automotive, computing, consumer, industrial, infrastructure, etc.
Go to www.monster.com or “Hot Jobs” on Yahoo and search under “statistician”
What careers are out there for Statisticians?
R&D Statistician – Materials: Corning Incorporated Corning is the world leader in specialty glass and ceramics.
We create and make keystone components that enable high-technology systems for consumer electronics, mobile emissions control, telecommunications and life sciences.
Statistician: Cetero Research Cetero Research is a leading provider of early clinical,
bioanalytical and specialty Phase II-IV research services to the bioanalytical, generic and pharma industries.
Statistician: WPS Health Insurance WPS Health Insurance is a large not-for-profit company that
has been in business for over 60 years. We offer health benefit plans to employer groups and individuals, administer Medicare benefits and serve U.S. military families world wide.
What education do you need to become a statistician?
A Bachelors degree is the absolute minimumWhile you can find jobs requiring only a B.S.
degree, you really should get a post grad. Degree (M.S. or Ph.D.)
At Merck, you cannot be hired as a statistician unless you have at least a Masters degree.
What can I expect if I pursue a degree in Statistics?
There will be a lot of (advanced) math Learning at least one major statistical computing
package is a must SAS, S-Plus, R, Minitab, JMP, etc Learning a computing language like Fortran or C++ can also
be useful If you have a keen interest in applying statistics to real
problems, then look for universities that encourage you to take science or engineering courses as electives and/or offers you the chance to work in a consulting lab.
A technical writing course is also very useful
Rough salary ranges for starting Statisticians
B.S.:$40,000 - $60,000M.S.: $60,000 - $90,000Ph.D.: $90,000 - $120,000
www.amstat.org/careers
Statisticians at Merck
All statisticians in R & D are part of BARDS (Biostatistics and Research Decision Sciences)
BARDS
Early Development
Statistics
Late Development
Statistics
Scientific Programming
EpidemiologyHealth
Economic Statistics
Statisticians at Merck
Early Development
Statistics
Biometrics Research
Nonclinical Statistics
Early Clinical Development
Statistics
Investigative Research
Personnel: - 9-Ph.D., 8-MS Statisticians - Senior Secretary - Stat Programmer - 3 Full-Time Consultants
Statisticians at Merck
Nonclinical Statistics (NCS) is responsible for providing experimental design and data analysis support to product and analytical development throughout MRL. We work together with research scientists and engineers to evaluate and implement efficient and effective experimental strategies, employ or guide our colleagues in the use of appropriate statistical methodologies to answer their research and development questions, and develop novel statistical methods to address previously unmet needs.
Why Study Statistics?
“Statistics is the Technology of the Scientific Method” – I. J. Good
Scientific Research
Statistics
Ann Landers survey
“A few weeks ago, a young married couple wrote to say they were undecided as whether or not to have a family. They asked me to solicit opinions from parents of young children as well as older couples whose families were grown. ‘Was it worth it?’ they wanted to know. ‘Were the rewards enough to make up for the grief?’ The question, as I put it to my readers, was this: ‘If you had it to do over again, would you have children?’ Well, dear friends, the responses were staggering. Much to my surprise, 70 per cent of those who responded [~10,000] said ‘no.’” Does this seem right? What could explain this result?
Ann Landers survey
This is an example of a biased statistic because the sample (even though it was very large) cannot be considered as being randomly drawn from the population. Why?
A national (scientific) survey asked the same question of 1373 randomly selected respondents, 91% responded “yes.”
Is this example still relevant today?
Are 16-year-olds safe drivers?
The following statistics suggest that 16-year-olds are safer drivers than people in their twenties, and that octogenarians are very safe. Is this true?
* This example comes from econoclass.com
Are 16-year-olds safe drivers?
No. As the following graph shows, the reason 16-year-old and octogenarians appear to be safe drivers is that they don't drive nearly as much as people in other age groups.
Moral: Think about the Data!
What do I do at Merck?
Assay ValidationRisk AssessmentTechnology transferProcess DevelopmentProduct Stability AssessmentSpecification SettingOut-of-Specification InvestigationsAnd a lot more
What do I do at Merck?
All of this work utilizes many of the basic statistical methods/calculations you have been exposed to Average, Standard Deviation, Percentages,
Probability, Normal and t-distributions, Confidence Intervals, Hypothesis Tests, etc,
And some you haven’t Regression, Variance Component Analysis, Mixed
Models, Equivalence Testing, 2 and F-Distributions, Outliers, Bayesian Methods, etc.
I function as part of a team consisting of chemists, biologists, engineers, and others.
Assay Validation
Potency: a measure of the activity of a drug in a biological system
Example: GARDASIL® Potency AssayMeasured as the antigen concentration or
antigen mass/unit volume in a biological matrix – Very critical to get good potency information on the lots we manufacture!
About GARDASIL®
About 30 types of HPV are known as genital HPV since they affect the genital area HPV Types 16 and 18 cause 70% of cervical cancer cases HPV Types 6 and 11 cause 90% of genital warts cases
GARDASIL® is a vaccine (injection/shot) that is used for girls and women 9 through 26 years of age to help protect against various diseases caused by Human Papillomavirus (HPV). It is also used for boys and men 9 through 26 years of age to help protect against genital warts
Target VLP Concentrations: Type 6: 20 µg VLP/mL Type 11: 40 µg VLP/mL Type 16: 40 µg VLP/mL Type 18: 20 µg VLP/mL
VLP stands for “virus like particles, which are non-infectious components of the virus that strongly activate the
immune response
Assay Validation Parameters
Accuracy Linearity Specificity Precision Repeatability Ruggedness Robustness LOD/LOQ Range
Bias
Variability
Sensitivity
Risk Assessment
Product: 15-Valency Vaccine Assays: Relative IC50 (rIC50) – One Assay
per Valency.Relative IC50 Assay
00.20.40.60.8
11.21.4
0.00001 0.0001 0.001 0.01 0.1 1 10 100Concentration
Ass
ay R
ead
ing Unknown
Standard
Horizontal Distance Represents the
Log(rIC50)
Risk Assessment
Current Procedure for Testing a Lot:Perform 3 assay runs per valency (Geometrically) average the 3 rIC50s
Laboratory Issues:Resource intensive – 3×15 = 45 runs per lotTakes 1 – 2 weeks to do all testing
Proposal:Only perform 2 runs and (geometrically)
average the corresponding rIC50s
Risk Assessment
Statistical Issues:1. What do you think? Hint: think standard
error2. Hard one! Obscure Hint: think lottery
winner
Risk Assessment
Questions:What is the risk that a “good” lot will fail at
release if only 2 runs are performed?What is the risk that a stable lot will fail at
least one time point during stability testing?Accounting for statistical multiplicity
What risk is acceptable?How should I address these questions?
Always Ask Questions!
A psychologist wishes to determine whether genetics (nature) or environment (nurture) plays the dominant role in terms of athleticism and intelligence. She has come to you for advice on how to design and analyze the study. What questions might you ask of her?
What do some People think about Statisticians?
Torture numbers, and they'll confess to anything. - Gregg Easterbrook (American Author)
A statistician is a professional who diligently analyzes data and then carefully draws confusions about them. – Anonymous.
If your experiment needs statistics, you ought to have done a better experiment. – Ernest Rutherford (Chemist/Physicist)
What do Statisticians think about Statisticians?
Ethical Guidelines for Statistical Practice: American Statistical Association Prepared by the Committee on Professional Ethics Approved by the Board of Directors, August 7, 1999
Statement:Because society depends on sound statistical
practice, all practitioners of statistics, whatever their training and occupation, have social obligations to perform their work in a professional, competent, and ethical manner...
www.amstat.org/committees/ethics