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Test Heuristics Cheat Sheet
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An educational tool to explore Risk Analysis and Quality Strategy building with the whole team.

Test Heuristics Cheat Sheet

Dive into the handy Test Heuristics Cheat Sheet, new and improved for today's modern testing professional. Support your testing efforts and generate test ideas.

Download a PDF edition. Visit the Lesson Resources at the end of this page.

Data Type Attacks

Paths/Files

Long Name (>255 chars)

Special Characters in Name (space * ? / \ | < > , . ( ) [ ] { } ; : ‘ “ ! @ # $ % ^ & ƒ )

Non-Existent

Already Exists

No Space

Minimal Space

WriteProtected

Unavailable

Locked

On Remote Machine

Corrupted

Time and Date

Timeouts

Time Difference between Machines

Crossing Time Zones

Leap Days

Always Invalid Days (Feb 30, Sept 31)

Feb 29 in Non-Leap Years

Different Formats (June 5, 2001; 06/05/2001; 06/05/01; 06-05-01; 6/5/2001 12:34)

Internationalisation dd.mm.yyyy, mm/dd/yyyy 

am/pm, 24 hoursƒ 

Daylight Savings Changeover

Reset Clock Backward or Forward

Numbers

0

32768 (215)

32769 (215 + 1) ƒ

 65536 (216)

65537 (216 +1)

2147483648 (231)

2147483649 (231 + 1)

4294967296 (232)

4294967297 (232 + 1)

Scientific Notation (1E-16)

Negative

Floating Point/Decimal (0.0001)

With Commas (1,234,567)

European Style (1.234.567,89)

All the Above in Calculations

Strings

Long (255, 256, 257, 1000, 1024, 2000, 2048 or more characters)

Accented Chars (àáâãäåçèéêëìíîðñòôõöö, etc.)

Asian Chars (  )

Common Delimiters and Special Characters ( “ ‘ ` | / \ , ; : & < > ^ * ? Tab )

Leave Blank

Single Space

Multiple Spaces

Leading Spaces

End-of-Line Characters (^M)

SQL Injection ( ‘select * from customer )

With All Actions (Entering, Searching, Updating, etc.)

Emojis

General

Violates Domain-Specific Rules (an ip address of 999.999.999.999, an email address with no “@”, an age of -1)

Violates Uniqueness Constraint

Web Tests

Navigation

Back (watch for ‘Expired’ messages and double-posted transactions)

Refresh

Bookmark the URL

Select Bookmark when Logged Out ƒ

Hack the URL (change/remove parameters; see also Data Type Attacks)

Multiple Browser Instances Open

Swipe/Tap/Pinch

Input

See also Data Type Attacks

HTML/JavaScript Injection (allowing the user to enter arbitrary HTML tags and JavaScript commands can lead to security vulnerabilities)

Check Max Length Defined on Text Inputs ƒ

 > 5000 Chars in TextAreas

Syntax

HTML Syntax Checker 

CSS Syntax Checker

Preferences

Javascript Off

Cookies Off

Security High

Resize Browser Window

Change Font Size

Accessibility / A11y

Keyboard: Navigation; Skip to link (first tab); No traps (menus / subsections); visible focus indicator; use all functionality; pop ups have focus, can be dismissed

Context: Links (descriptive) ; Alt-text (descriptive or decorative is hidden); Form input labels; Main elements (only one) Country and language defined; plain language used;

Content: Capitals in #; No all capitals text; No justified text; Zoom to 200%; Gender neutral; acronyms explained; clear instructions; Good contrast; More than just colour to indicate success e.g. green tick

API Tests

BINMEN

(Gwen Diagram & Ash Winter)

Boundary, Invalid Entries, NULL, Method, Empty, Negative

POISED

(Amber Race)

Parameters, Output, Interop, Security, Errors, Data

VADER

(Stuart Ashman)

Verbs, Authorisation/Authentication, Data, Errors, Responsiveness

Mobile/Device/Tablet

MOBILE APP TESTING

(Daniel Knott)

Mobile Device, Orientation, Mobile Browsers, Interrupts, Look, Energy Consumption, Automation, Performance, Personas, Time & Date, Ergonomics, Security, Tracking, Inputs, Network, Platform Guidelines.

Testing Wisdom
A test is an experiment designed to reveal information or answer a specific question about the software or system.
Stakeholders have questions; testers have answers.
Don't confuse speed with progress.
Take a contrary approach.
Observation is exploratory.
The narrower the view, the wider the ignorance.
Big bugs are often found by coincidence.
Bugs cluster.
Vary sequences, configurations, and data to increase the probability that, if there is a problem, testing will find it.
It's all about the variables.
I am not all humans, not everyone does things as I do.
Heuristics

Variable Analysis 

Identify anything whose value can change. Variables can be obvious, subtle, or hidden.

TouchPoints

Identify any public or private interface that provides visibility or control. Provides places to provoke, monitor, and verify the system.

Boundaries

Approaching the Boundary (almost too big, almost too small), At the Boundary

Goldilocks

Too Big, Too Small, Just Right

CRUD

Create, Read, Update, Delete

Follow the Data

Perform a sequence of actions involving data, verifying the data integrity at each step. (Example: Enter → Search → Report → Export → Import → Update → View)

Configurations

Varying the variables related to configuration (Screen Resolution; Network Speed, Latency, Signal Strength; Memory; Disk Availability; Count heuristic applied to any peripheral such as 0, 1, Many Monitors, Mice, or Printers)

Interruptions

Log Off, Shut Down, Reboot, Kill Process, Disconnect, Hibernate, Timeout, Cancel

Starvation

CPU, Memory, Network, or Disk at maximum capacity

Position

Beginning, Middle, End (Edit at the beginning of the line, middle of the line, end of the line)

Selection

Some, None, All (Some permissions, No permissions, All permissions)

Count

0, 1, Many (0 transactions, 1 transactions, Many simultaneous transactions)

Multi-User

Simultaneous create, update, delete from two accounts or same account logged in twice.

Flood

Multiple simultaneous transactions or requests flooding the queue e.g. making/selecting a submit request/button multiple times

Dependencies

Identify “has a” relationships (a Customer has an Invoice; an Invoice has multiple Line Items). Apply CRUD, Count, Position, and/or Selection heuristics (Customer has 0, 1, many Invoices; Invoice has 0, 1, many Line Items; Delete last Line Item then Read; Update first Line Item; Some, None, All Line Items are taxable; Delete Customer with 0, 1, Many Invoices)

Constraints

Violate constraints (leave required fields blank, enter invalid combinations in dependent fields, enter duplicate IDs or names). Apply with the Input Method heuristic.

Input Method

Typing, Copy/Paste, Import, Drag/Drop, Various Interfaces (GUI v. API)

Sequences

Vary Order of Operations ƒ Undo/Redo ƒ Reverse ƒ Combine ƒ Invert ƒ Simultaneous

Sorting

Alpha v. Numeric ƒ Across Multiple Pages

State Analysis

Identify states and events/transitions, then represent them in a picture or table. Works with the Sequences and Interruption heuristics.

Map Making

Identify a “base” or “home” state. Pick a direction and take one step. Return to base. Repeat.

Users & Scenarios

Use Cases, Soap Operas, Personae, Extreme Personalities

RCRCRC

(Karen N. Johnson)

Recent - what testing around new areas of code should I think about?

Core - what essential functions or features must continue to work?

Risky - what features or areas of code are inherently more risky?

Configuration Sensitive - what code is dependent on environment settings? 

Repaired - what code has changed to address defects and potentially created issues?

Chronic - what code typically breaks features that need to be tested?

FAILURE

(Ben Simo)

Functional, Appropriate, Impact, Log, UI, Recovery, Emotions

WWWWWHKE

(sounds like “wiki” (Darren McMillan)

Who is this for? What is this for? When & by whom is it to be done? Where is it being done? Why is it being done? How is it being achieved? What questions does my Knowledge & Experience produce?

Diversity & Inclusion

(Callum Akehurst-Ryan)

Combat Bias with Heuristics of Diversity

(Ash Coleman)

Does this work for me? Does this work for them? Does this work for someone I have never considered or ever met?

Seven Dwarfs

(Cassandra H. Leung)

Grumpy, Happy, Sleepy, Bashful, Sneezy, Dopey, and Doc.

Specs/Designs Watchlist

(Gerard McCann)

Ambiguity, weasel words (like could, should or may), Fudge (e.g. statements like ‘this will be resolved at a later date’, but no specifics around who and when), Confusing terminology, jargon or obscure acronyms, Oversimplification, Overcomplication

TORCH

(Simon Tomes)

Timer, Oracles, Risks, Consider these questions, Heuristics

MCOASTER

(Michael Kelly)

Mission, Coverage, Obstacles, Audience, Status, Techniques

Environment, Risk

Seen and Heard

(Ady Stokes)

For everything you can see, is it announced by a screen reader? For everything you hear, can it be read (transcript, subtitles, captions, audio descriptions)

TuTTu and TaTTa

(Mark Winteringham)

Testing the UI or Testing Through the UI

Testing the API or Testing Through the API

SACRED

(Richard Bradshaw)

State Management, Actions, Codified Oracle, Reporting, Execution, Deterministic

TRIMS

(Richard Bradshaw)

Targeted, Reliable, Informative, Maintainable, Speedy

Frameworks

Judgement 

(James Lyndsay)

Inconsistencies, Absences, and Extras with respect to Internal, External – Specific, or External – Cultural reference points.

Observations 

(James Lyndsay)

Input/Output/Linkage

Flow

Input/Processing/Output

Requirements 

(Gause & Weinberg)

Users/Functions/Attributes/Constraints

Nouns & Verbs

The objects or data in the system and the ways in which the system manipulates it. Also, Adjectives (attributes) such as Visible, Identical, Verbose and Adverbs (action descriptors) such as Quickly, Slowly, Repeatedly, Precisely, Randomly. Good for creating random scenarios.

Deming’s Cycle

Plan, Do, Check, Act

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Copyright © 2006 Quality Tree Software, Inc. and Copyright  © 2022 Ministry of Testing Ltd.

This cheat sheet includes original ideas from Elisabeth Hendrickson, James Lyndsay, and Dale Emery.

And further ideas from Andrea Jensen, Ady Stokes, Callum Akehurst-Ryan, Dave Harrison, Deborah Sherwood, Mark Winteringham, and Simon Tomes.

Simon Tomes
Community Lead at Ministry of Testing
he/him
Hello, I'm Simon. I've had various roles in testing, tech leadership and coaching since 2003. I believe in the power of collaboration, creativity and community.
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