Logical Operator Icons

Question

I'm building a WPF UI for configuring some complex business rules; each rule can have many conditions, so I figured I would include a drop-down list of logical operators so that the user could have the flexibility required by the business case.

Basically a rule has a logic and a behavior, and under each rule, each condition also has a logic:

• Rules' behavior is one of the following:

  • RuleConditionsMustPass: this means a rule is said to pass when the logical operations of all conditions under it evaluate to true.
  • RuleConditionsMustFail: this means a rule is said to pass when the logical operations of all conditions under it evaluate to false.

• Rules' logic can be one of the following:

  • And: all rules with an "And" logic must pass.
  • Or: among all rules with an "Or" logic, at least one must pass.
  • Xor: among all rules with an "Xor" logic, only one must pass.

• Similarly, conditions' logic works the same way: given a "RuleConditionsMustPass" behavior, the rule will pass if all "And" conditions pass and if among all "Or" conditions at least one passes and among all "Xor" conditions only one passes.

What I'm wondering, is whether the icons I've chosen for each logical operator make any sense from a UX point of view, and if using a TreeView for this rule configuration feature is the best approach:

Clicking the green "+" button here would add a condition under that rule; clicking the red "-" button would delete that rule. I realize the ComboBox.ItemTemplate is a bit off here, when I'm done with it I'll make sure all items in the dropdown have the same width, and I won't be using the enum names in the directly in the UI.

Answer 1

The icons are alright, but I would consider the terminology in general.

• OR - Same as "match any of the following rules"?
• AND - Same as "match all of the following rules"?
• XOR - Same as "match one of the following rules"? At least if there are only 2 options to pick from... If there are more than 2 it gets more complicated.

Maybe it's enough just to have Match all / match one / match any / match none to cover all options, together with the possibility to nest rules.

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Example (Itunes Smart Playlists):

Answer 2

Use Venn-diagram symbols as icons.

OR = two overlapping circles, both colored in.

AND = two overlapping circles, overlapping area colored in.

XOR = two overlapping circles, all but overlapping area colored in.

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Example from Google search:

Edit:

A few comments:

1. The icons in the question don't make logical sense, one is a branch icon, another is a merge icon and I am not sure what the third symbolizes. Logical diagrams that do explain the operators are either Venn diagrams which are easy to understand or switch diagrams, which may seem strange to many users.

2. XOR is absolutely NOT a "one of" operator, its a "odd (uneven) number of conditions are true" operator.

3. It doesn't usually matter to simple users if one condition is true or multiple ones.

4. In a rule system, you need to let users define operators such as NOT and () brackets, otherwise users will have to complicate their rules e.g. X XOR X AND Y OR X XOR X AND Z instead of NOT X AND (Y OR Z).

See this question and its answers for a way to visualize this.