Sign Language Proficiency Interview

The Sign Language Proficiency Interview (SLPI) uses a conversational approach with the purpose to assess sign language communication skills, considering both function and form and support people in the development of their sign language communication skills (Caccamise & Newell, 1995, 1999a; Newell et al., 1983). The SLPI is based on the Language Proficiency Interview (LPI)/Oral Proficiency Interview (OPI), which was developed to assess the communicative competence in a foreign or second language. The LPI/OPI was adapted for the SLPI. The SLPI has been developed at the National Technical Institute for the Deaf (NTID), Rochester Institute of Technology, USA. In the following, only the SLPI version developed at the NTID will be presented.

The SLPI seemed to be broadly used in different settings, ranging from staff at vocational rehabilitation settings, university faculty, students, and many more (Caccamise & Newell, 1999a, p. 1).

The interview takes about 15 to 25 minutes. Through its character of a conversational approach, it assesses both language production and comprehension of the test taker. Communicative competence is defined by how well a person can communicate with other people, considering both function and form.

The design of the SLPI is a one-to-one interview situation with the interviewer and the test-taker. They converse/talk about different topics and contents varying in accordance with the interests, job responsibilities, and communications needs of the candidate. The performance was videotaped and subsequently rated by three raters who are familiar with the SLPI methodology.

The SLPI rating scale is “a predetermined standard scale based on highly skilled, knowledgeable native or non-native signer” (Caccamise & Newell, 1995, p. 33). It is rather a criterion-referenced test, because each candidate’s performance is compared to a predetermined, standard performance scale, which is based on the ideal language user than to other candidates (Newell et al., 1983). The rating scale rates signing that occurs along a natural sign language continuum, from ASL to more English-like forms.

The different rating levels of the SLPI Rating Scale range from “Superior Plus” over a eleven point scale to “No Functional Skills”. Here a few examples:

Superior Plus: to be able to have a fully shared and natural conversation, with in-depth elaboration for both social and work topics and all aspects of signing are native-like. [...] No Functional Skills: maybe to be able to provide short single sign and ‘primarily’ fingerspelled responses to some basic questions signed at slow rate with extensive repetitions and rephrasing (Caccamise & Newell, 1999a, p. 6).

The results of the SLPI may be used to assist in planning signed language skill- development opportunities. The important concepts for assessing sign language communication skills focus on form and function. Form focuses on (1) vocabulary knowledge, (2) production of signing, (3) fluency, (4) grammar, and (5) comprehension. On the functional side, the pragmatic/functional use of signing for work and social communication is assessed, including if the candidate can have a conversation, as well as sociolinguistic/cultural knowledge (Caccamise & Newell, 1999a).

After a candidate has been interviewed and rated, he/she will have a follow-up meeting with the interviewer in order to review the videotaped interview, discuss the candidate’s skills, and make him/her suggestions for improving sign language communication skills.

Reliability and validity for the Sign Communication Proficiency Interview have not been reported in-depth. One study about the reliability of the SLPI has been reported. Validity has not yet been reported.

A reliability study for the SLPI, conducted in 1996 by the NTID, focuses on the following three questions: “(1) how consistent are raters in interpreting the SLPI Rating Scale?, (2) how consistent are ratings within SLPI Ratings Teams (3 rater per team)?, and (3) how consistent are ratings across SLPI Rating Teams” (Caccamise & Newell, 1999b, p. 29). The results reveal that for “(1) the NTID SLPI raters are able to consistently interpret the SLPI Rating Scale, (2) ratings by three raters within SLPI Rating Teams are consistent with one another, and (3) reveals preliminary results that ratings across NTID SLPI Rating Teams are consistent” (Caccamise & Newell, 1999b, p. 34-35). Further reliability studies are planned.

Three types of rating of the videotaped interview have been reported. For example in the first one, three raters watch a videotape together, and each of them provides independent rating. Assuming that all three raters are in agreement (all within one half-level of one another), they write a report that provides an official rating (all raters need to agree on one rating), a description of the candidate’s sign language communication skills, and suggestions for improving these skills if appropriate. This process of rating took three raters 1 to 1 1/2 hours (Caccamise & Newell, 1999c).

Because the SLPI uses a conversational approach, a one-to-one situation, it might be more relaxing for the candidate than a typical test situation where he/she needs to react to test items. Additionally, the SLPI does not focus on the production and comprehension of specific linguistic structures in ASL, it rather provides a broader view on the communicative competence of the candidate.

The National Technical Institute for the Deaf (NTID) offers trainee workshops for the SLPI.

Among the strengths of the SLPI are that (1) it is interactive, (2) it emphasizes on communicative functioning, (3) the interviewer and the test-taker use communicative strategies, e.g. asking, answering, clarifying questions, turn-taking, (4) communicative needs of the candidate determined specific topics discussed, (5) assist in planning sign communication skills development opportunities appropriate for each candidate.

Among the weakness of the SLPI is that (1) it does not provide in in-depth information on the psychometric properties.


From:  Tobias Haug: “Review of Sign Language Assessment Instruments”, an earlier version of that paper 2005.

For more information regarding this test, please visit the  SLPI Website.