Activity
Evidence-based Management: It’s Not an Oxymoron!
Our Journey So Far…
Defining BS
Detecting BS (logically)
Describing where and why BS thrives
Deciphering BS (statistically)
Detecting BS (methodologically)
Distributions P-values Power
Confidence Intervals Effect Sizes
Proxies & Ecological fallacy
Research Designs Strategies & Studies
“The Lingo” Threats to Validity
Toward Evidence-based Practice Evidence-based practice is about making decisions through
the conscientious, explicit, and judicious use of the best available evidence from multiple sources by
Asking: Translating practical issues/problems into answerable questions1
Acquiring: systematically searching for and retrieving the evidence2
Appraising: critically judging quality of the evidence3
Aggregating: Weighing and pulling together the evidence4
Applying: Incorporating evidence into decision-making processes5
Assessing: Evaluating decisions to increases success probabilities6
The Challenge of Practicing EBM
Evidence-based practice ignores practitioners’ professional experience ✗
Evidence-based practice is all about numbers, analytics, & statistics ✗
Managers need to make decisions quickly & don’t have time for EBM ✗
Each company is unique, so usefulness of scientific evidence is limited ✗
If you do not have high-quality evidence, then you cannot do anything ✗
Good-quality evidence gives you the direct or perfect answer ✗
False beliefs about EBM
Sources of Evidence
Scientific Literature (empirical studies)
Organization (internal data)
Practitioners (professional expertise)
Stakeholders (values and concerns)
Sources of Evidence
Scientific Literature (empirical studies)
Organization (internal data)
Practitioners (professional expertise)
Stakeholders (values and concerns)
Organizational Facts (and Errors)
Small Numbers Range Restriction
Measurement Error Confounds
Example: Using last year’s average to predict/forecast next year’s
numbers (e.g., sales)
Example: Profiling “top performers” to develop criteria to
use in personnel selection
Example: Using difference scores to indicate financial performance
(e.g., profitability)
Example: Examining the impact of training but not controlling for
trainee attributes (e.g., motivation, cognitive ability)
Organizational Facts (and Errors)
Small Numbers Range Restriction
Measurement Error Confounds
Solutions: aggregate data across units or time; use confidence intervals; form collaborations
(industry/regional groups)
Solutions: examine more than just extreme cases; apply statistical correction for range restriction
Solutions: use multiple indicators; split differences into component
parts for analysis; correct for unreliability
Solutions: use control variables; aggregate data sets across units;
study the variables over time
The Pitfall of Patterns (and Intuition)
Trust me…20 years of management experience
What Good Theory Does
ü Organizes (parsimoniously) and communicates (clearly) ü Helps identify and define key problems ü Provides a basis for making predictions ü Gives meaning to observations (i.e., aids interpretation) ü Scopes empirical investigations (i.e., important variables) ü Permits generalization beyond the focal sample
Ultimate goal of theory is to explain… Why?!? (how & when too)
Why Are Fads So Compelling? § Promise effectiveness and efficiency (fast!) § Appear simple and readily implementable § Help assuage anxieties about problems § Make users feel ‘cutting edge’ § Often offer ‘half-truths’ (things that might work
sometimes, in some contexts)
What tells you that a model is probably a fad?
Some Telltale Signs of a Fad § Too simple, straightforward
§ Easy to communicate, reduces to a very small number of factors § Promise (even guarantee) results
§ Fad auteurs are confidently didactic – no false humility or hedging § Universal applicability
§ Solutions for everyone, everywhere § Aligned with zeitgeist
§ Resonates with trends or problems du jour § Novel, but not radical
§ Question assumptions; but rediscovers/repackages older ideas § Lively, entertaining
§ Articulate, bold, memorable; buzzwords, lists, acronyms, etc. § Legitimacy via gurus and star examples
§ Supported by stories of “best companies” and the status of gurus
*Miller, Hartwick, LeBreton-Miller (2004)
Sources of Evidence
Scientific Literature (empirical studies)
Organization (internal data)
Practitioners (professional expertise)
Stakeholders (values and concerns)
EBM in Action: The CAT