Five Essential Heuristics Every Tester Should Know

Ministry of Testing launched a LinkedIn newsletter at the start of 2023. Each newsletter article has got a lot of attention which is awesome. Each one celebrates someone in the community who has produced something that’s been published on the MoT platform. Written by me or Sarah Deery – based on our own interpretations and experiences.

So I thought, why not bring them onto The Club to spark conversations, share ideas, celebrate and debate?

Heuristics spark test ideas and generate questions to support testing efforts. Heuristics come in many shapes and sizes. Here are five essential heuristics every tester should know.


CRUD stands for Create, Read, Update and Delete. Think of it as the things you might want to do with an entity within a system. For example, can I create a new customer record? Can I view it? Does it match the data I input when I created it? Can I change the record? And what happens if I attempt to delete the customer record?

2. Selection

Some, None, All. For example, do I have permission to delete all customer records? Or does this particular user permission only allow me to delete some or none at all?

3. Boundaries

What boundaries should you test? Is there a limit to the number of customer records I can view on this device? View just before the boundary, at the boundary and attempt to view beyond the boundary.

4. Constraints

Violate the constraints. Leave required fields blank when creating a new customer record. Enter invalid combinations in dependent fields. What happens when I create a customer record where I know it’s a duplicate? How soon can I delete a new customer record? What input methods are accepted? Can I type, copy/paste or drag/drop?

5. Follow the Data

What varied sequences of actions can I take to observe data integrity? For example, delete a customer record > view customer record > create customer record > create another customer record > create another customer record > attempt to view the original customer record. Via API and GUI. Is the data in the state you expected it to be?

Want more heuristics and helpful triggers to spark test ideas? Read the Test Heuristics Cheat Sheet — with two handy downloadable PDFs. :page_facing_up::page_facing_up:

The cheat sheet includes original ideas from the brilliant Elisabeth Hendrickson, James Lyndsay, and Dale Emery. With further ideas from Andrea Jensen, Ady Stokes, Callum Akehurst-Ryan, Dave Harrison, Deb Sherwood, Mark Winteringham, and Simon Tomes.

How about you, what are your go-to heuristics? What ones typically help you?


This morning I was asking my son to do something and he’s taken to replying with “Never” :neutral_face: And he then turned around and said “Always”.

And I think to myself, “Does he already know the Never and Always heuristic?” :thinking::sweat_smile: