12 things about product-market fit

So what are considered some of the best tests for PMF (product market fit)? Rachleff writes that “You know you have fit if your product grows exponentially with no marketing. That is only possible if you have huge word of mouth. Word of mouth is only possible if you have delighted your customer.” Tying together the concepts, Rachleff also shares that entrepreneurs too often confuse product/market fit with growth in what Ries calls vanity metrics (“numbers or stats that look good on paper, but don’t really mean anything important”). So what does? Rachleff suggests Net Promoter Score (NPS) as a great tool to predict the magnitude of customer love for one’s product/service — ideally a score of 40 or higher “to know you’re on the right track.” However, while NPS is a pretty good proxy for likely fit, it is “not nearly as accurate as having market feedback in the form of purchases.” People vote with their dollars, after all.

Marc Andreessen writes: “In a great market — a market with lots of real potential customers — the market pulls product out of the startup.” Ideally in the easiest stages of a product development process pull is happening organically (i.e., without any advertising spending).

12 Things about Product-Market Fit

Ed Tech Developer’s Guide

Ten opportunities for technology to transform teaching & learning:

  • Improving mastery of academic skills
  • Developing skills to promote lifelong learning
  • Increasing family engagement
  • Planning for future education opportunities
  • Designing effective assessments
  • Improving educator professional development
  • Improving educator productivity
  • Making learning accessible to all students
  • Closing opportunity gaps
  • Closing achievement gaps


Brain dump



“So why don’t I like edutainment? The problem is with the way that creators of today’s edutainment products tend to think about learning and education. Too often, they view education as a bitter medicine that needs the sugar-coating of entertainment to become palatable. They provide entertainment as a reward if you are willing to suffer through a little education. Or they boast that you will have so much fun using their products that you won’t even realize that you are learning—as if learning were the most unpleasant experience in the world … I also have a problem with word “edutainment” itself. When people think about “education” and “entertainment,” they tend to think of them as services that someone else provides for you. Studios, directors, and actors provide you with entertainment; schools and teachers provide you with education. New edutainment companies try to provide you with both. In all of these cases, you are viewed as a passive recipient. That’s a distorted view. In fact, you are likely to learn the most, and enjoy the most, if you are engaged as an active participant, not a passive recipient.”


Editorial: The evolving field of tangible interaction for children: the challenge of empirical validation

“This editorial has called for caution in relation to an a priori assumed superiority of tangibility …

we advised going beyond the idea of TUIs as the antithesis of GUIs, especially when comparative evaluations are made, arguing instead for a closer link with theoretical abstractions (e.g., the various theoretical frameworks that have been proposed to characterize tangibility … ) and for more scientific rigor in empirical studies.”

from Editorial: the evolving field of tangible interaction for children: the challenge of empirical validation 

Some other notes from this paper.

The arguments about the benefits of TUIs are generally:

  • improved usability
  • potential learning benefits – linking concrete manipulations and cognition
  • fun
  • collaboration.

However there is not a great depth of research backing these claims. Most of the research around TUIs focus around design innovation.

“Spatial organization as a mnemonic of relationships between items, which in turns facilitates recognition.”

There may not be advantages of TUIs when compared to GUIs.

Some evidence suggests TUIs are not inherently more usable than a GUI for kids 5-7.

Toolkits for kids embody a constructionist philosophy.

For example, Arduino.

Some broad educational theory argues the benefit of concrete manipulation.

For example, Montessori and Frobel.

Piaget also argued that cognitive development takes place by gradual abstraction from sensorimotor experience.

Also Bruner – enactive learning. “Hands-on” learning.

No real research beyond links to these “broad brush” educational theories.

There is some evidence that TUIs may increase collaborative play, and there may be some emotional, cognitive and motor control benefits from TUIs.

The research in this area focuses on kids with ASD and cognitive impairments.

There’s also quite a bit in this editorial about defining and measuring fun, but none of the research seems to ask the kids of they are having fun, which to me seems a bit weird. TUIs do, to me, seem fun.


In summary, there’s not compelling evidence, beyond perhaps increase collaboration, that TUIs will increase learning.

However I wonder if that comes down to what is being taught.


Osmo and tangible user interfaces (TUI) – a brain dump really

After trying the LittleBits kit I thought Osmo might be a good next stop for exploration.

There is something intriguing about the interplay between physical objects and digital systems, I think. Loads of possibilities. But is it designer bullshit or are there really evidence-based learning outcomes for kids when they learn using this kind of stuff.

TUI academic papers

This lead me down a garden path into HCI academia.

Tangible User Interfaces – Past, Present and Future Directions


This is a foundational piece of work for anyone new to TUIs.

From history to theory to frameworks and then on to available code libraries for hacking your own prototype, this was a valuable couple of hours of reading.

Cognitive Dimensions of Tangible Programming Languages


Radia Perlmann, MIT – teaching kids to code in the 70s

Remember programming a turtle to do stuff. https://turtleacademy.com/lessons/en

TORTIS was the work of Radia Perlmann,  Radia Perlman, working at the Massachusetts Institute of Technology, developed the first technological means allowing preliterate children to perform computer-programming. An aside – how have I not heard of Radia Perlmann before?


A programmable frog thing based on Perlmann’s work is included in the Australian Curriculum examples for teaching younger grade kids the basics of programming concepts.

Still to read

Literature Review in Learning with Tangible Technologies


From turtles to Tangible Programming Bricks: explorations in physical language design


Conceptualising tangibles to support learning

And even more to explore

All roads lead back to MIT with this kind of stuff …