ISCA International Workshop on Speech and Language Technology in Education (SLaTE 2011) Venice, Italy August 24-26, 2011

Readability Index as a Design Criterion for Elicited Imitation Tasks in Automatic Oral Proficiency Assessment

Febe de Wet (1,2), Pieter Müller (2), Christa van der Walt (3), Thomas Niesler (2)

(1) Human Language Technology Competency Area, CSIR Meraka Institute, Pretoria, South Africa.
(2) Department of Electrical and Electronic Engineering, Stellenbosch University, South Africa.
(3) Department of Curriculum Studies, Stellenbosch University, South Africa.

We investigate the effectiveness of using an accepted readability index, the Flesch Reading Ease (FRE) scale, to design prompts for an automatic oral proficiency assessment system. The prompts in question are uttered by the system, and must be repeated from memory by the test subjects, in the form of an elicited imitation exercise. The FRE scores for our prompts are shown to correlate well with the repeat accuracy ratings given to the same prompts by human judges. The prompts are also shown to perform well in the automatic assessment of oral proficiency by means of the elicited imitation tasks with more than one group of university students. We therefore conclude that a readability index, such as the FRE, can be used as a design criterion for prompts in an automated elicited imitation test.
Index Terms. elicited imitation task, readability index, Flesch Reading Ease scale, automatic oral proficiency assessment

Full Paper

Bibliographic reference.  Wet, Febe de / Müller, Pieter / Walt, Christa van der / Niesler, Thomas (2011): "Readability index as a design criterion for elicited imitation tasks in automatic oral proficiency assessment", In SLaTE-2011, 105-108.