I was somewhat inspired by Gunter Sachs' research efforts. He had spent 'about the same amount as the factory price of an exclusive British sports car' on a study into Sun Signs in a book entitled The Astrology File. He published his results around the same time I started my research in 1997.
Rather than look at zodiac signs I looked at planets. My first study began around 1997, but the serious data gathering started in 2000. In the meantime I looked at how I could successfully experiment with astrological progressions (effectively a means to make the horoscope move through time). By 2000 I was sure of my method which was to gather public record relationships for the time of meeting or marriage and to measure the interaspects of the Sun, Venus and Mars between both the natal and progressed charts of the two partners
I chose a method of data gathering that eliminates selectivity. This method is commonly used when investigating large-scale organized crime. Criminal Network Analysis was slightly modified to Celebrity Network Analysis and involved mapping all of the known intimate relationships of individuals for which accurate data exists. These connections extend widely in public relationships.
Between 2000 and 2004 I gathered 1300 well-attested public relationships. I measured the interaspects and published my results in 2006 in the book When Stars Collide.
Between 2006 and 2018 I gathered a second set and in 2019 repeated the first experiment. The results are discussed in the second edition of my book A 22nd Century Science.
In April 2021, after seven years of peer review by both astrology skeptics and practitioners, an article describing the experiments and the results was published in the journal of research in astrology, Correlation Vol 33 (2) 2021. It took over a year just to write the article Astrology using Progressed Synastry in 1,300 Public Cases - A Validation Study. This was the culmination of twenty-two years of research.
The results for both experiments showed that astrological aspects play a role in relationship choice. When combined the probability that the results came about by chance was 21 sextillion to one against, but more importantly, the results explained why we have had such difficulty expressing the truth of astrology - we have simply been looking at it from the wrong perspective.
In terms of time and materials, the two experiments cost a bit over 2 million US dollars and took twenty two years to complete.