Related Experiment Video
Updated: Oct 14, 2025

A Machine Learning Approach to Design an Efficient Selective Screening of Mild Cognitive Impairment
Published on: January 11, 2020
An alternative screening approach for Google Search identifies an accurate and manageable number of results for a
Simon Briscoe1, Morwenna Rogers1
1University of Exeter Medical School, University of Exeter, Exeter, UK.
Background:
A challenge when using Google Search to identify studies for a systematic review is managing the high number of results, which can number in the hundreds of thousands or even more. Studies and guidance on web searching suggest limiting the screening process, e.g. to the first 100 results.
Objectives:
Our objective in this case study is to demonstrate an alternative approach to screening the results retrieved by Google Search which is based on our experience that the viewable number of results is often far fewer than the estimated number calculated by the search engine.
Methods:
We screened the results of three searches of Google Search using our approach, which involves increasing the number of results displayed per page from 10 to the maximum of 100. We then calculated the viewable number of results and compared this with the estimated number.
Results:
The mean of the estimated number of results for the three searches was 569,454,000. The mean of the viewable number results was 463 (0.00008% of the mean of the estimated number of results).
Conclusion:
Our findings challenge the commonly reported view that the number of results retrieved when using Google Search is too high to screen in full.
Related Concept Videos
Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...
Comparing the Survival Analysis of Two or More Groups
Systematic Sampling Method
Systematic sampling is one of the simplest methods...
Randomized Experiments
Simple randomization
Simple...
Strategies for Assessing and Addressing Confounding
Confounding can be addressed at both the design phase of a study and through analytical methods after data...
Bioequivalence Experimental Study Designs: Repeated Measures, Cross-Over, Carry-Over, and Latin Square Designs

