Masha Bertling.
AI evaluation · Causal inference · Measurement

Better evidence.
Better decisions.

I’m Masha, a Senior Scientist at Amazon. I build AI evaluation systems, design experiments and quasi-experimental studies, and develop the measurement and structural models that tell teams what a result means.

I stay hands-on in the research and lead the scientists and engineers around it: choosing defensible methods, setting validation standards, and turning evidence into decisions people can act on.

Amazon / Senior ScientistHarvard / Ph.D.MIT · J-PAL / Measurement Fellow · Randomized evaluationsSeattle / Washington
01 / Research approach

Different methods.
A consistent standard.

The question determines the method. Across AI evaluation, causal studies, measurement, and structural models, I ask what supports the conclusion, and what would change it.

  1. AI evaluation & validation

    Where does the model fail—and does the result generalize?

    I build human-grounded evaluations, analyze where LLM judges and human raters disagree, and break errors down by category. I use regression checks to compare models and prompts, and I validate the reference data itself before trusting it.

    A high aggregate agreement rate can hide a weak category. Agreement with human labels also does not establish that the labels capture the right thing.

  2. Causal inference & quasi-experiments

    What variation identifies the effect?

    I design experiments and quasi-experimental studies around the causal question, the assignment process, and the available comparison. I assess identification, run diagnostics, quantify uncertainty, and show how results move under different assumptions.

    A comparison group has to be credible for the question being asked. Similar pre-trends are a diagnostic; they do not establish the identifying assumption.

  3. Measurement & psychometrics

    Are we measuring the intended construct?

    My psychometrics training shapes how I design and validate measures. Before interpreting a change in a score, I check comparability, composition, and uncertainty.

    When the mix of respondents changes, a score can move even if the underlying experience does not.

  4. Structural economic models

    What assumptions support the counterfactual?

    I use structural models to make assumptions about behavior explicit and to examine counterfactuals. I assess identification, fit, and sensitivity to establish what a model can and can’t tell us.

    A model can fit observed behavior while supporting very different counterfactual predictions under alternative assumptions.

02 / Scientific leadership

Research depth.
Shared scientific direction.

I work from the individual research problem to the standards a team can use.

I lead scientists and engineers, set the methodological and validation standards they work to, and work across disciplines with senior decision-makers. I stay close to the research while helping others frame questions and assess evidence.

Team leadership

Led eight scientists
and engineers

Scientific standards

Methods and validation
across disciplines

Decision areas

AI evaluation, measurement
and intervention impact

Frame the consequential question.

Clarify the decision, the estimand, and the evidence needed. Surface assumptions and choose a design that can support the intended claim.

Build standards people can reuse.

Make diagnostics, validation criteria, uncertainty reporting, and scientific review explicit enough to carry across projects and teams.

Connect findings to judgment.

Communicate what is known, what remains uncertain, and which tradeoffs belong to the decision-maker. Help collaborators challenge the conclusion productively.

03 / Research

Selected publications

Treatment-effect heterogeneity, measurement quality, and the interpretation of evidence.

2025

Heterogeneity of Item-Treatment Interactions Masks Complexity and Generalizability in Randomized Controlled Trials

Ahmed, I., M. Bertling, L. Zhang, A. D. Ho, P. Loyalka, H. Xue, S. Rozelle, and B. W. Domingue.

Journal of Research on Educational Effectiveness, 18(4): 854–877.

Why this matters

An average treatment effect can hide differences in how individual test items respond to an intervention. The paper examines what those differences mean for interpretation and uncertainty. For AI evaluation, this raises a related question: does an overall benchmark gain extend across the items that matter?

2025

Psychometric Quality of Measures of Learning Outcomes in Low- and Middle-Income Countries

Bertling, M., A. Singh, and K. Muralidharan.

In Handbook of Experimental Development Economics, edited by U. Dasgupta and P. Maitra. Edward Elgar Publishing.

Why this matters

Before comparing results across settings, check what the tests measure, how reliably they measure it, and whether the scores are comparable. This chapter examines those questions for learning outcomes.

2018

Using Response Time Data to Reduce Testing Time in Cognitive Tests

Bertling, M., and J. P. Weeks.

Psychological Assessment, 30(3): 328–338.

Why this matters

Response-time information can support shorter cognitive tests while preserving measurement precision. The study examines when incorporating that information into the model makes shorter forms possible.

04 / Background

A statistician’s habits.
A scientist’s curiosity.

I began in psychometrics, studied policy evaluation and statistics at Harvard, and worked on measurement and randomized experiments at MIT and J-PAL. At Amazon, my work spans causal inference, structural modeling, measurement, and AI evaluation.

These fields share questions I care about: what is identified, what is measured, what assumptions do the work, and how far a conclusion can travel.

I have also taught statistics, people analytics, and data science at Harvard and Harvard Business School.

Amazon

Senior Scientist · Research Scientist

MIT / J-PAL

Measurement Fellow · Randomized evaluations

Harvard University

Ph.D., Policy Evaluation and Statistics
A.M., Statistics · Ed.M., Education

Educational Testing Service

Psychometric research

05 / Start a conversation

Let’s connect.

For research conversations, collaborations, and professional opportunities, connect with me on LinkedIn.

Connect on LinkedIn