Itamar Gilad believes there are two kinds of companies - evidence-guided and opinion-based - and whilst the concepts were developed during two decades spent in product management and engineering roles at companies including Google and Microsoft, they can equally be applied to growth marketing and experimentation.

What Itamar is getting at here is two very different kinds of companies - those that rely heavily on opinions in decision-making, and those that rely on evidence.

• Opinion-based: Rely on opinions, Hide uncertainty, Focus on output metrics, Prioritise planning and execution, Plans dictated by smart people making blind bets, A planning mindset

• Evidence-guided: Rely on evidence, Embrace uncertainty, Focus on outcome metrics, Prioritise hypotheses and idea evaluation, Plans rooted in data, logic and evidence, An experimentation mindset

"Evidence-guided companies understand there’s a lot of uncertainty in the game and are tilting the odds in their favor. Opinion-based companies are effectively placing blind bets on a roulette table. You may get rich both ways, but one works much more consistently."

Itamar Gilad

Itamar strongly believes product development is full of uncertainty, and that by rooting decisions in evidence, you are dramatically increasing your chances of success.

"Done right, evidence-guided approaches improve resource efficiency, reduce planning time, suppress politics, build trust, empower people and teams, and, most importantly, deliver value to the business and to the customers faster."

Itamar Gilad

We believe marketing is also full of uncertainty, and advocate for a similar evidence-guided (rather than opinion-based) approach.

For more information see Itamar's new book - Evidence Guided: Creating High-Impact Products in the Face of Uncertainty. You can also find Itamar on LinkedIn here and on Twitter here.