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Washington State Institute for Public Policy
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Tutoring: Supplemental computer-assisted instruction for English language learners (ELL)

Pre-K to 12 Education
Benefit-cost methods last updated December 2023.  Literature review updated March 2020.
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Supplemental computer-assisted instruction (CAI) reflects education that supplements rather than replaces regular classroom instruction. In this analysis, supplemental CAI provides reading instruction to students who are English language learners (ELL) and are struggling with reading.

Supplemental CAI is provided after school to improve English language comprehension and reading performance. Students participate in CAI for four to five weekly, 20-minute lessons for an entire school year. In the included study, CAI was provided to elementary-aged students using the Imagine Learning software. The analysis excludes studies that focus exclusively on special education populations. The study in the analysis compares students receiving English comprehension and reading CAI to students who receive other forms of tutoring that aim to improve English comprehension.
For an overview of WSIPP's Benefit-Cost Model, please see this guide. The estimates shown are present value, life cycle benefits and costs. All dollars are expressed in the base year chosen for this analysis (2022). The chance the benefits exceed the costs are derived from a Monte Carlo risk analysis. The details on this, as well as the economic discount rates and other relevant parameters are described in our Technical Documentation.
Benefit-Cost Summary Statistics Per Participant
Benefits to:
Taxpayers $2,582 Benefits minus costs $11,616
Participants $6,083 Benefit to cost ratio $69.27
Others $3,206 Chance the program will produce
Indirect ($85) benefits greater than the costs 69%
Total benefits $11,786
Net program cost ($170)
Benefits minus cost $11,616

Meta-analysis is a statistical method to combine the results from separate studies on a program, policy, or topic in order to estimate its effect on an outcome. WSIPP systematically evaluates all credible evaluations we can locate on each topic. The outcomes measured are the types of program impacts that were measured in the research literature (for example, crime or educational attainment). Treatment N represents the total number of individuals or units in the treatment group across the included studies.

An effect size (ES) is a standard metric that summarizes the degree to which a program or policy affects a measured outcome. If the effect size is positive, the outcome increases. If the effect size is negative, the outcome decreases. See Estimating Program Effects Using Effect Sizes for additional information.

Adjusted effect sizes are used to calculate the benefits from our benefit cost model. WSIPP may adjust effect sizes based on methodological characteristics of the study. For example, we may adjust effect sizes when a study has a weak research design or when the program developer is involved in the research. The magnitude of these adjustments varies depending on the topic area.

WSIPP may also adjust the second ES measurement. Research shows the magnitude of some effect sizes decrease over time. For those effect sizes, we estimate outcome-based adjustments which we apply between the first time ES is estimated and the second time ES is estimated. We also report the unadjusted effect size to show the effect sizes before any adjustments have been made. More details about these adjustments can be found in our Technical Documentation.

Meta-Analysis of Program Effects
Outcomes measured Treatment age No. of effect sizes Treatment N Adjusted effect sizes(ES) and standard errors(SE) used in the benefit - cost analysis Unadjusted effect size (random effects model)
First time ES is estimated Second time ES is estimated
ES SE Age ES SE Age ES p-value
5 2 813 0.187 0.107 5 0.058 0.117 17 0.187 0.080
1In addition to the outcomes measured in the meta-analysis table, WSIPP measures benefits and costs estimated from other outcomes associated with those reported in the evaluation literature. For example, empirical research demonstrates that high school graduation leads to reduced crime. These associated measures provide a more complete picture of the detailed costs and benefits of the program.

2“Others” includes benefits to people other than taxpayers and participants. Depending on the program, it could include reductions in crime victimization, the economic benefits from a more educated workforce, and the benefits from employer-paid health insurance.

3“Indirect benefits” includes estimates of the net changes in the value of a statistical life and net changes in the deadweight costs of taxation.
Detailed Monetary Benefit Estimates Per Participant
Affected outcome: Resulting benefits:1 Benefits accrue to:
Taxpayers Participants Others2 Indirect3 Total
Test scores Labor market earnings associated with test scores $2,582 $6,083 $3,206 $0 $11,871
Program cost Adjustment for deadweight cost of program $0 $0 $0 ($85) ($85)
Totals $2,582 $6,083 $3,206 ($85) $11,786
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Detailed Annual Cost Estimates Per Participant
Annual cost Year dollars Summary
Program costs $354 2018 Present value of net program costs (in 2022 dollars) ($170)
Comparison costs $204 2018 Cost range (+ or -) 40%
The cost of the supplemental computer-assisted instruction (CAI) can vary widely based on the number of students in each school using the program and the number of students using the program at one time. The interventions included in this review required an average of 1.9 hours of teacher time per student over a school year. The comparison students also received teacher time because they participated in other supplemental tutoring. We estimate the difference in teacher-time across the groups and the per-participant cost of the program used in the interventions included in the analysis. We estimate that the per-participant cost is $150 for the program Imagine Learning Language & Literacy software, the program used by all treated students in the analysis, in 2018 dollars (retrieved from
The figures shown are estimates of the costs to implement programs in Washington. The comparison group costs reflect either no treatment or treatment as usual, depending on how effect sizes were calculated in the meta-analysis. The cost range reported above reflects potential variation or uncertainty in the cost estimate; more detail can be found in our Technical Documentation.
Benefits Minus Costs
Benefits by Perspective
Taxpayer Benefits by Source of Value
Benefits Minus Costs Over Time (Cumulative Discounted Dollars)
The graph above illustrates the estimated cumulative net benefits per-participant for the first fifty years beyond the initial investment in the program. We present these cash flows in discounted dollars. If the dollars are negative (bars below $0 line), the cumulative benefits do not outweigh the cost of the program up to that point in time. The program breaks even when the dollars reach $0. At this point, the total benefits to participants, taxpayers, and others, are equal to the cost of the program. If the dollars are above $0, the benefits of the program exceed the initial investment.

Citations Used in the Meta-Analysis

Cassady, J.C., Smith, L.L., & Thomas, C.L. (2018). Supporting emergent literacy for English language learners with computer-assisted instruction. Journal of Research in Reading, 41(2), 350-369.