```r
print(survey_data)
```

```
## # A tibble: 8 x 3
##      id variable value
##   <dbl> <chr>    <dbl>
## 1     1 var1       1  
## 2     1 var2       0.2
## 3     2 var1       1.4
## 4     2 var2       1.9
## 5     3 var1       0.1
## 6     3 var2       2.8
## 7     4 var1       1.7
## 8     4 var2       1.9
```

```r
nested_data = survey_data %>%
  nest(variable, value)

print(nested_data)
```

```
## # A tibble: 4 x 2
##      id data            
##   <dbl> <list>          
## 1     1 <tibble [2 x 2]>
## 2     2 <tibble [2 x 2]>
## 3     3 <tibble [2 x 2]>
## 4     4 <tibble [2 x 2]>
```