# What is the difference between equivalence partitioning and decision tables techniques

I need to know the different situations when can I use equivalence partitioning technique and when to use decision table technique. A lot of situation I feel that I can use equivalence partitioning instead of decision table and vice versa. In the example below (I got it from guru site). Decision table technique is used, my question we don't use equivalence partitioning?. Please advice

Example: Consider a dialogue box which will ask the user to upload a photo with certain conditions like – You can upload only '.jpg' format image file size less than 32kb resolution 137*177.

• Equivalence Partitioning and Decision Tables are two very different things - are you sure that's what you're meaning to compare? – trashpanda Mar 19 '18 at 8:35
• Your example is missing. – FDM Mar 19 '18 at 8:49
• I need to know when each technique is used. this is what I meant by "What is the difference between the two techniques" – Simon Jishi Mar 19 '18 at 10:12
• Simon Jishi, could you point a scenario where there might be confusion regarding which one to use ? – Vishal Aggarwal Mar 19 '18 at 11:23

The website you're referencing has very good explanations and examples of decision tables and equivalence partitioning (used below). These are very different techniques and can't be used interchangeably.

Decision table testing is a testing technique used to test system behavior for different input combinations.

For example:

Whereas Equivalance Partitioning is testing technique used to divide the set of test conditions into partitions, and then a single value from each of those partitions are tested.

For example:

So here, the only valid input is a number between 1 and 10. Anything outside of that range is considered invalid.

If you're still confused, I'd recommend re-reading the two articles and noting down the highlights and differences - it's pretty clear imho.

Edit: Also check out these explanations, examples and definitions from istqbexamcertification.com on Decision Tables and Equivalence Partitioning

• but in the scenario I gave above, I can use equivalence partitioning technique. Example: The image format input can be partitioned into jpg as valid input and another format as invalid input Size can be partitioned can also partition into 32 as valid and > 32 as invalid. Same applies for resolution. After partition, we can derive test cases. For this, I have asked when can we use the techniques. – Simon Jishi Mar 19 '18 at 12:55
• @SimonJishi. Well, your example is more like a switch - it's either less than 32kb, or more than 32kb. The same goes for the format and resolution... they're either true or false, which is ideal for decision tables. Equivalence Partitioning doesn't really work in your example, so you wouldn't use it here. – trashpanda Mar 19 '18 at 13:22