Table 1 Hypothetical data for two single-item Likert instruments (n = 10)

Score i

Frequency f _i

$f_i^2$

Score i

Frequency f _i

$f_i^2$

1

1

1

1

8

64

2

2

4

2

0

0

3

4

16

3

1

1

4

2

4

4

0

0

5

1

1

5

1

1

Sum

26

66