María Teresa Ortiz

Data Scientist | Lecturer

Biography

I am a data analyst with experience in ecology and marketing, I currently work in CONABIO (Mexico’s National Commission of Biodiversity) doing statistical analysis related to biodiversity.

I also enjoy teaching, I teach statistics courses to master students in Data Science and to bachelors in Mathematics and Actuarial Sciences at ITAM.

Lastly, I love R, I am co-organizer of R-Ladies CDMX and often deliver custom R training (introduction to R, survey data analysis in R,…).

Interests

Statistical modeling (hierarchical models, spatial statistics, Bayesian networks)
Survey design and Survey data analysis
Machine learning
Data visualization

Education

MA Statistics, 2013

University of Michigan
Summer Program for Survey Statisticians, 2013

University of Michigan
BSc in Applied Mathematics, 2009

ITAM

Experience

Advisor

CONABIO

Jul 2014 – Present Mexico City

I primarily work in a project for biodiversity monitoring based on large scale in situ collections of sound, photographs, and videos.

Responsibilities include:

Advise and participate in the development of statistical models, for example, the modeling of ecological integrity with Bayesian belief networks.
Develop R packages and shiny applications meant to analyze sounds, to generate automatic reports, and to visualize the information stored in our databases.

Lecturer

ITAM

Jan 2014 – Present Mexico City

Courses Taught:

MSc Data Science: Computational Statistics, Multivariate Statistics, Mathematical Statistics with Resampling.
BSc Mathematics/BSc Actuarial Sciences: Exploratory Data Analysis and Survey Sampling.

Undergraduate Thesis Advisor:

Andres Sanudo. Analysis of the demand for parking space in Mexico City, BSc in Mathematics, 2015.
Beatriz Ambia. Conjoint analysis case study with Stan, BSc in Mathematics, 2019.

Data Analyst

LQL

Jun 2009 – Mar 2011 Mexico City

LQL is a consulting firm focused in marketing research and predictive modeling.

Responsibilities include:

Performed analysis of survey data (market segmentation, conjoint analysis) and participated in survey design.
Designed and implemented automatic reports for survey based studies.
Developed computational tools in R and Python to improve the efficiency of the analysis area.

Projects

COVID-19 State-Level estimates for Mexico

We adapted the semi-mechanistic Bayesian hierarchical model of COVID-19 epidemiological dynamics found in Flaxman et al. (2020) to produce state-level estimates of the number of infections and the time-varying reproduction number (the expected number of secondary cases caused by each infected individual) as a function of human mobility. Here we explain the model in detail and the assumptions made for Mexico and here we show state-level estimates. We also published an article in the Mexican newspaper Nexos explaining the model results here.

Quick-count MX

In Mexico quick-counts take place whenever major elections take place. For the quick-counts a probabilistic sample of polling stations is selected in advance and estimates are presented in the election night. The complete samples are rarely available to publish the results in a timely manner hence the results are announced using partial samples which have biases. We developed a Bayesian hierarchical model that includes demographic and geographic covariates, the model reduces the biases associated to such covariates. Here we explain the model in detail and here is an R package with the model implementation, and here is a published paper with the methodology for one of the models we used.

Teaching

Computational Statistics (spanish)

I teach a course in Computational Statistics for the master programs in Data Science and in Computer Science at ITAM. Felipe González and I developed the syllabus and I developed (and yearly update) the class notes. Here is the latest course site and here is the GitHub repository with the class notes.

Multivariate Statistics (spanish)

In 2014 and 2015, I taught a course in Multivariate Statistics (covering Bayesian Networks, Markov Random Fields HMMs, hierarchical models,..) for the master program in Data Science at ITAM. Felipe González and I developed the syllabus and the class notes. I am in the process of updating the course resources, here is the course site and here is a Github repository with class notes.

Introduction to R for data analysis (spanish)

Notes for a 3-4 day introductory workshop to R for data analysis. Here is the workshop site and here is the GitHub repository. I have taught this workshop (sometimes as part of a larger program) at ITAM, CONABIO, SAI, OXFAM Mexico, GNP and COLMEX.

Exploratory Data Analysis and Survey Sampling (spanish)

I taught a course in Exploratory Data Analysis and Survey Sampling for bachelors in Mathematics and Actuarial Sciences at ITAM. I am in the process of uploading the material (developed by Felipe Gonzalez).