Why the Best Managers Build Evidence Instead of Borrowing Opinion
- Raffles Jakarta
- Aug 6
- 9 min read
The decision is made during the final ten minutes of the meeting. Someone leans back and says, "In my experience, this is how strong companies operate," before naming one. Someone else points out that a competitor tried the same thing and it worked. A third person recalls a line from a book by a well-known CEO.
Heads nod. The plan was approved. Nobody in the room has asked the only important question: how do we know any of this is true? This is how a large amount of management is done. Not with malice or laziness, but rather with borrowed conviction.
The most authoritative-sounding input in most meetings is not a finding, but rather a confident opinion disguised as fact and passed around the table until it hardens into a decision. Best practices are copied from companies whose circumstances no one has investigated. Gurus' advice is repeated as if it were law.
A manager's own hard-earned experience, which is genuine but limited, is treated as if it resolved the issue for everyone. And the best managers, those whose judgment quietly turns out to be correct more often than not, tend to do something slightly unconventional and unpopular.
They want to know where the belief came from. They regard a confident claim as the start of an investigation rather than the conclusion of one. They build evidence rather than borrowing opinions, and over time, that difference leads to something that looks like wisdom.
The most persuasive voice in most meetings is not the best-informed one. It is the most confident one.
Management's most common mistake is borrowing its beliefs
The problem is not new, and it has been diagnosed with unusual bluntness. In a foundational argument for a different way of working, two Stanford scholars observed that managers looking to improve their organizations mostly rely on obsolete knowledge from their training, long-standing traditions that were never tested, patterns half-remembered from personal experience, and the marketing of consultants and vendors.
Too many, they wrote, adopt other companies' "best practices" without ever asking whether those practices will transfer to their situation (Pfeffer & Sutton, 2006). They offered a now-famous illustration.
When United Airlines set out to compete with Southwest in the 1990s, it copied the surface of Southwest's model, the casual uniforms, the single aircraft type, and the quick turnarounds without grasping the system of evidence and choices underneath it. The imitation failed because United had borrowed the appearance of a practice rather than the understanding behind it (Pfeffer & Sutton, 2006). This behavior is the signature error of management by opinion: it copies conclusions while ignoring the reasoning that produced them.
The cost is not abstract. Reviewing decades of organizational practice, researchers at the Center for Evidence-Based Management estimated that billions are spent every year on management practices that have been shown to be ineffective or even harmful, precisely because decisions are anchored in fashion, imitation, and personal belief rather than in what the evidence supports (Barends, Rousseau, & Briner, 2014).
What evidence-based management actually is
The alternative has a name. Evidence-based management is the practice of making decisions through the conscientious, explicit, and judicious use of the best available evidence from multiple sources (Barends, Rousseau, & Briner, 2014).
The idea was crystallized when Denise Rousseau asked, in a widely cited address, whether such a thing as evidence-based management could even exist and used evidence-based medicine as the model for closing what she called the research-practice gap: the persistent failure of organizations to base their practices on the best available knowledge of what works (Rousseau, 2006).
The phrase is often misheard as a demand for more spreadsheets, but that misses its meaning. Evidence-based management does not mean drowning a decision in numbers.
It means drawing deliberately on four different sources at once: findings from scientific research, reliable data from inside the organization, the considered judgment of experienced practitioners, and the values and concerns of the people a decision will affect (Barends, Rousseau, & Briner, 2014). Crucially, it means appraising the quality of each of those sources rather than accepting whichever is loudest. Evidence is not the same thing as data, and neither is the same thing as a strongly held opinion.
Evidence is not the same as data, and neither is the same as a strong opinion stated firmly.
Seen this way, the discipline is less about information and more about a habit of mind. A manager practicing evidence-based management asks, "What is the best available evidence, how good is it, and what does it actually say?" rather than "What do I believe?"
The evidence that opinion is usually wrong
It would be easy to dismiss all of these findings as a matter of preference, one management philosophy versus another. However, the disparity between what practitioners believe and what research demonstrates has been measured, and the findings are sobering.
In a landmark study, researchers polled thousands of human resource professionals to see how much they agreed with well-established findings from their field. The 959 responses revealed large, consistent discrepancies between practitioner belief and evidence, particularly in the high-stakes area of hiring, where managers placed far less faith in the predictive power of well-validated selection methods than the research indicated (Rynes, Colbert, & Brown, 2002).
The significance of that discovery is easily underestimated. These were not careless people; they were experienced professionals who confidently held beliefs and ran organizations based on those beliefs, despite the accumulated evidence in their discipline contradicting them. If the people whose job it is to know what works are so frequently wrong about it, the confident opinion circulating in an ordinary meeting deserves far more scrutiny than it currently receives.
Why the confident gut is not enough
There is a deeper reason to distrust borrowed conviction, and it reaches into how human judgment itself operates. Across a remarkable range of fields, from predicting academic performance to forecasting criminal behavior, researchers have repeatedly compared expert intuition against simple, transparent statistical rules.
The verdict has been consistent for decades: the structured, evidence-based method usually matches or beats the seasoned expert working from judgment alone (Dawes, Faust, & Meehl, 1989). More striking still, adding a confident human to a well-designed evidence-based procedure often makes it worse rather than better.
In the hiring context, layering managerial gut feeling on top of a validated selection process has been shown to produce poorer decisions than following the evidence would have (Rousseau & Barends, 2011). The intuition feels like it is adding value. The outcomes say otherwise. Part of the explanation is that the confident mind is a biased instrument.
Even the most experienced teams fall into confirmation bias, anchoring, and overconfidence, quietly dismissing evidence that contradicts a favored recommendation and giving too much weight to whatever is vivid or first. Simply being aware of these biases does little to correct them; what helps is subjecting a recommendation to a structured, deliberate review of the process behind it, not just the conclusion (Kahneman, Lovallo, & Sibony, 2011).
The problem is not that managers have intuitions. It is that they so rarely check them.
None of these findings implies that intuition is worthless. Experience is genuine evidence, and a practitioner's judgment is one of four valid sources. The point is more specific and useful: unexamined intuition is untrustworthy, and the discipline of building evidence exists precisely to test it, ensuring that sound instincts survive contact with reality and bad instincts are caught before they become decisions.
Building evidence is a practice, not a personality
The encouraging part is that this skill is common and not limited to a select few. It is a repeatable procedure that any manager can learn. Practitioners of evidence-based management follow a recognizable sequence: they translate a vague concern into a clear, answerable question; gather evidence from all four sources rather than the most convenient one; assess the credibility of that evidence; weigh it together; apply it to the decision; and then assess the outcome to determine whether the decision was effective (Barends, Rousseau, & Briner, 2014).
That final step, honest evaluation, is where most organizations quietly opt out, but it is also where the compounding advantage exists. Managers who actively seek disconfirming evidence, looking for reasons to be wrong, consistently make better decisions than colleagues who rely solely on their first instinct (Rousseau & Barends, 2011).
The payoff is more than just philosophical. When companies incorporate these habits into how big decisions are made, the results improve: a large review of major business investments found that organizations that worked deliberately to remove bias from their decision process earned materially higher returns than those that did not (Kahneman, Lovallo, & Sibony, 2011).
Building evidence is a habit any manager can learn, not a gift a few happen to possess.
Why this is the skill that separates the best managers
Borrowing opinion is always faster. It conveys authority, enhances experience, and ensures that a meeting ends on time. Building evidence takes longer, can be awkward at times, and requires a manager to say, "I'm not sure that's true; let's find out" in front of a room full of people who would rather move on.
However, the manager who is tasked repeatedly is the one whose track record gradually separates from everyone else's, because their decisions are based on reality rather than whoever spoke last with the most conviction. This is why the underlying capability is worth intentionally developing. Analytical thinking, or the ability to reason from evidence rather than assertion, is now regarded by the world's largest employers as one of the most important skills for the future workforce, and it, like any other skill, can be taught and strengthened rather than left to chance.
The most effective managers are not born skeptics. They are trained and conditioned to ask how we know.
Where managers learn to build evidence
This process is exactly where a broad, rigorous postgraduate business education comes into its own, and it is important to be specific about what it provides. It does not provide a manager with a larger pool of opinions to borrow. It gives them the discipline to question opinions, including their own, and reason based on the best available evidence in whatever function they lead.
That discipline is the design of the Raffles Jakarta MBA.
The Raffles MBA prepares ambitious professionals to lead with confidence through an integrated curriculum, practical business insight, and an international learning environment.
The MBA Program at Raffles Jakarta
Research methodology is taught alongside accounting for decision making, managerial economics, and strategic management so that managers learn to evaluate the quality of a claim, read the numbers behind it, and connect the evidence to a decision, rather than treating each as a separate world. Defending your thinking to a cohort who does not share your assumptions for an entire year is evidence-based training: every conclusion must withstand questions about where it came from.
The result is a graduate who reaches for evidence by instinct, not opinion by default.
As part of Raffles Education, which was founded in Singapore in 1990 and now operates 16 colleges in 14 cities across nine countries, a degree earned here belongs to an international network rather than a single market.
The manager who asks how we know
The distinction between a competent manager and a confident one is rarely one of intelligence and almost never one of nerve. It is a matter of where their beliefs originate.
The manager who borrows opinions is only as competent as the last person they persuaded. The manager who builds evidence is creating something long-term: a method of decision-making that becomes more accurate as evidence accumulates and does not collapse when a charismatic voice enters the room.
The habit of basing a decision on what is actually known rather than what is confidently asserted does not make a manager cautious or slow. It makes them trustworthy, and over time it makes them correct.
Learning to build evidence rather than borrowing opinions is one of the most long-lasting ways to THINK BIGGER!
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References
Barends, E., Rousseau, D. M., & Briner, R. B. (2014). Evidence-based management: The basic principles. Center for Evidence-Based Management. https://cebma.org/assets/Uploads/Evidence-Based-Practice-The-Basic-Principles.pdf
Dawes, R. M., Faust, D., & Meehl, P. E. (1989). Clinical versus actuarial judgment. Science, 243(4899), 1668–1674. https://doi.org/10.1126/science.2648573
Kahneman, D., Lovallo, D., & Sibony, O. (2011). Before you make that big decision. Harvard Business Review, 89(6), 50–60. https://hbr.org/2011/06/the-big-idea-before-you-make-that-big-decision
Pfeffer, J., & Sutton, R. I. (2006). Evidence-based management. Harvard Business Review, 84(1), 62–74. https://hbr.org/2006/01/evidence-based-management
Pfeffer, J., & Sutton, R. I. (2006). Hard facts, dangerous half-truths, and total nonsense: Profiting from evidence-based management. Harvard Business Review Press. https://casbs.stanford.edu/hard-facts-dangerous-half-truths-and-total-nonsense-profiting-evidence-based-management
Rousseau, D. M. (2006). Is there such a thing as "evidence-based management"? Academy of Management Review, 31(2), 256–269. https://doi.org/10.5465/amr.2006.20208679
Rousseau, D. M., & Barends, E. G. R. (2011). Becoming an evidence-based HR practitioner. Human Resource Management Journal, 21(3), 221–235. https://doi.org/10.1111/j.1748-8583.2011.00173.x
Rynes, S. L., Colbert, A. E., & Brown, K. G. (2002). HR professionals' beliefs about effective human resource practices: Correspondence between research and practice. Human Resource Management, 41(2), 149–174. https://doi.org/10.1002/hrm.10029
World Economic Forum. (2025). The future of jobs report 2025. https://www.weforum.org/publications/the-future-of-jobs-report-2025/
Raffles Jakarta. (2026a). Master of Business Administration. https://www.raffles-indonesia.com/mba
Raffles Jakarta. (2026b). Think bigger: The Raffles Jakarta MBA 2026. https://www.raffles-indonesia.com/think-bigger-mba-jakarta
