Study experience on selection calculation and some PDF distributions

Sandra Vega, Universidad Nacional Autónoma de Mexico, Centro de Geociencias


The purpose of this exercise is to use the concept of cut-off (selection calculations) in sample data and the application of grade/tonnage curves.
On successful completion of this exercise, the participant should be able to: (a) Produce selection calculations, and (b) Graph those calculations as grade/tonnage curves.

Learning Goals

- Concepts to be learn: (a) selection calculations, and (b)grade/tonnage curves.
- MATLAB is used here only as a tool to reach a better understating of concepts. Making the graphs by their own in MATLAB helps to consolidate theoretical concepts on data analysis.
- The higher-order skill to be developed in this activity is data analysis.
- The other skill that the students may develop in this lab activity is writing.

Context for Use

- This lab exercise was tailored for a 3rd year undergraduate course on "Data Analysis and Geostatistics".
- It is a lab practical exercise to be performed during lab-clases. It may take between 1 to 2 hours, depending on the level of the participants.
- The participants should have some experience in MATLAB but there is not need to be proficient as all steps to follow are giving in detail. The most important point here is that the participants get the concepts.
- The students should be familiar on basic concepts of statistics such as population, mean , median, histograms, PDF.
- This activity is relatively easy, just enough to learn/consolidate the concepts of cut-off (selection calculation) and PDFs. 
- The technical skills that the students should have is just to be able to open MATLAB windows and type commands. 

Description and Teaching Materials

The complete lab activity is attached here as a PDF file. MATLAB is used to guide the students to follow step by step for performing their own data analysis on a data set of heights and study the targeted concepts.

The activity in this exercise could be done in other software, or simply in Excel, indeed. However, my idea was that the students started to get familiar with MATLAB, so they could used it later for their other clases, research, and graduation projects.

The textbook used for the theory was: Isobel Clark and William Harper, 2001, Practical Geostatistics 2000. ISBN-10: 0970-33172-X

Handout - Lab Exercise on selection calculations (Acrobat (PDF) 281kB Sep8 20)
Data example for the lab exercise on selection calculations (Excel 17kB Sep8 20) 


Teaching Notes and Tips

You can adapt this lab exercise to your students heights or any other interesting data for your course. I usually asked the students their heights the first day of class, and collected the data. Then, we worked the rest of the semester on it. Therefore, every new group of students had different statistics. From my experience, it is interesting to see how the students identify themselves with the data and they are more engaged in the data analysis. So, I suggest that you adapt the cut off to each group accordingly. Also, I would like to share that even my intention was that the students could get familiar with MATLAB, I don't think they learned much about MATLAB... My guess is that as we did give them every single step to follow, they did not have to make any effort to learn the tool, so they only followed the instructions.


I usually graded the lab exercise and also the post lab exercise to evaluate how much they have learned and met the goals.

References and Resources

There is not web references for this lab activity.