According to the ILH, tasks with a higher involvement load are considered to be more effective for word learning and retention than tasks with lower involvement loads. For comparison purposes, each task is assigned a specific number which relates to an involvement load index. Total absence of a factor is assigned 0, a moderate presence is assigned 1 and strong presence is assigned a score of 2.
(0) Absent: Learner doesn’t need to understand or produce word.
(1) Moderate: Learner is required to learn the word by external source (teacher).
(2) Strong: Learner makes decision to learn or produce the word.
(0) Absent: Meaning or translation of word is provided.
(1) Present: Learner must look up meaning / translation of a word.
(0) Absent: Words are not compared with other words.
(1) Moderate: Words are compared to other words in provided contexts.
(2) Strong: Words are compared to other words in self-created contexts.
For example, if a teacher provides students with some new words and their definitions and asks students to create original sentences with them, the task would be assigned the following involvement load score:
Need: Moderate, (1): the assignment is imposed by the teacher.
Search: Absent (0): the definitions are provided.
Evaluation: (2) High: the students need to write their own original sentences.
Total Score: 3
The results of the test found that retention of the new vocabulary directly correlated with involvement load. Participants who had completed tasks with the lowest involvement load scored lowest and those who had completed tasks with the highest involvement load scored highest. This provides evidence in support of the ILH.