selectby tag - 'steps'

The selectby tag with the steps method (alias step or stepwise) defines a multi-step selection process for variables, allowing different selection rules at each step.

set list: BRANDS 
1. Coke
2. Dr Pepper
3. Pepsi
4. Sprite
5. Diet Coke
6. Mountain Dew
7. Coke Zero
8. Diet Pepsi
9. Fanta
10. Canada Dry Ginger Ale

7. Which of the following brands have you heard of? 
type: checkbox 
optsfrom: BRANDS

8. Which of the following brands have you ever purchased? 
type: checkbox 
optsfrom: BRANDS {if anyChecked($Q7,[id])}
99. None

9. Which of the following brands have you purchased in the past three months? 
type: checkbox 
optsfrom: BRANDS {if anyChecked($Q8,[id])} 
99. None

10. Which brand is your favorite? 
type: radio 
optsfrom: BRANDS

BRANDS. 2 Brands for deep dive
type: quotas
selectby: steps
optsfrom: BRANDS
maxgroups: 2
steps:
1. Primary brand {if anyChecked($Q10,[id])} {maxgroups: 1} {selectby: condition}
2. Purchased competitor [1,3,5,7,8] {if anyChecked($Q8,[id])} {maxgroups: 1} {selectby: condition}
3. Recent brand {if anyChecked($Q9,[id])} {maxgroups: 2} {selectby: counts}
4. Other brands {if anyChecked($Q7,[id])} {maxgroups: 2} {selectby: counts}

Details

• selectby: steps can be used on type: checkbox, type: coded multiple select, and  type: quotas questions.
• The selectby: steps variable requires that a maxgroups tag be included at the parent level.
• The selectby: steps process cannot be combined with other selection methods and cannot be used at the same time as the cross by tag.
• Each step must have the following decorators: a condition, maxgroups, and selectby.
• apply if can be included on any steps that should only be applied to certain respondents..
• If needed, you can filter the option set with inclusion/exclusion and option data syntax.
• Steps are evaluated in the order they are programmed.
• By default, selectby: steps automatically creates a unique variable to store the data for each step. The step variables are located in the Survey fields chapter along with the parent step variable. Apply the steps chapter tag to change the step question's location in the reporting field tree.

Understanding step selection behaviors

There are several step behaviors that are helpful to understand.

1. An item selected in an earlier step cannot be chosen in a later step.
2. Step selections keep a running count of the total selected items. A later step cannot exceed the remaining number needed, regardless of the maxgroups allowance on that step.
3. Each step establishes its own selectby process.
   • A step's selection process can be tiered, such as selectby: counts, weight.
   • A step cannot use selectby: steps, selectby: percentage, or selectby: balance in its own selection process.

Additional examples

Including and excluding options

BRANDS. 2 Brands for deep dive
type: quotas
selectby: steps
optsfrom: BRANDS
maxgroups: 2
steps:
1. Colas ever purchased [1,3,5,7,8] {if anyChecked($Q8,[id])} {maxgroups: 1} {selectby: condition}
2. Non-colas ever purchased -[1,3,5,7,8] {if anyChecked($Q8,[id])} {maxgroups: 1} {selectby: condition}
3. Any soda heard of {if anyChecked($Q7,[id])} {maxgroups: 2} {selectby: counts}

Using 'apply if' at the step level

GEN. What is your gender?
type: radio
1. Male
2. Female

set list: COLORS
1. Red    {{mweight: 2}} {{fweight: 0}}
2. Blue   {{mweight: 2}} {{fweight: 0}}
3. Yellow {{mweight: 2}} {{fweight: 0}}
4. Orange {{mweight: 0}} {{fweight: 2}}
5. Purple {{mweight: 0}} {{fweight: 2}}
6. Green  {{mweight: 0}} {{fweight: 2}}

COL. Which colors are you aware of?
type: checkbox
opts from: COLORS

2COLOR. Pick colors
type: coded multiple select
maxgroups: 2
selectby: steps
opts from: COLORS
steps:
1. Men {if anyChecked($QCOL,[id])} {maxgroups: 2} {selectby: weight} {weight: [mweight]} {apply if: anyChecked($QGEN,1)}
2. Women {if anyChecked($QCOL,[id])}  {maxgroups: 2} {selectby: weight} {weight: [fweight]} {apply if: anyChecked($QGEN,2)}