Table 2 Autism Diagnostic Interview-Revised (ADI-R) algorithm items sorted by number

31

Use of other’s body to communicate

I

33

Stereotyped utterances and delayed echolalia

III

34

Social verbalization/chat

II

35

Reciprocal conversation

II

36

Inappropriate questions or statements

II

37

Pronominal reversal

II

38

Neologisms/idiosyncratic language

II

39

Verbal rituals

III

42

Pointing to express interest

II

43

Nodding

II

44

Head shaking

II

45

Conventional/instrumental gestures

II

47

Spontaneous imitation of actions

II

48

Imaginative play

II

49

Imaginative play with peers

I

50

Direct gaze

I

51

Social smiling

I

52

Showing and directing attention

I

53

Offering to share

I

54

Seeking to share enjoyment with others

I

55

Offering comfort

I

56

Quality of social overtures

I

57

Range of facial expressions used to communicate

I

58

Inappropriate facial expressions

I

59

Appropriateness of social responses

I

61

Imitative social play

II

62

Interest in children

I

63

Response to approaches of other children

I

64

Group play with peers (age <10.0 years)

I

65

Friendships (age >10.0 years)

I

67

Unusual preoccupations

III

68

Circumscribed interests

III

69

Repetitive use of objects or interest in parts of objects

III

70

Compulsions/rituals

III

71

Unusual sensory interests (highest score of 69/71)

III

77

Hand and finger mannerisms (highest score of 77/78)

III

78

Other complex mannerisms or stereotyped body movements

III