One of the attacks that "skeptics" throw at astrology is that it gives overly subjective predictions and is based on subjective validation and a strong desire to believe. Of course their real objection to astrology is that since it is based on spiritual connections and the spiritual doesn't exist, obviously astrology is impossible. Nevertheless, they are on to something. It is easy to be overly gullible as astrologers since we do want to believe in astrology!
One way to fool yourself, and this is so prevalent that it is very hard to see it as problematic, is judging charts where the outcome is known or you know the events in the life of the person whose chart it is. I tried to demonstrate this with the chart of someone I identified as a serial killer and yes could see a lot of Scorpionic and 8th house influence in the chart, but the chart actually turned out to be Gandhi's! The response to this chart and posting was interesting. It was generally ignored, except I got a few posts saying that Gandhi was like a serial killer.
Certainly we cannot rely on the subjective feelings of clients. Even with horary, which is much more focused and precise than natal, clients' feedback is usually "wow, you got it 100% right" or occasionally "that was completely wrong". In fact, when I find out the facts generally I am not 100% accurate, but the occasional client reporting inaccuracy in the prediction is off base as well. How do I know this?
My practice is to always do my analyses in writing. This way I have an accurate record of what I told the client. Without this we are left trying to remember exactly what we said and have no real basis for determining the accuracy of the prediction. In addition, we have a record of what our prediction was before we knew the outcome. Then when I get feedback, I go back to the original reading, check it and then add the results.
Therefore as far as I am concerned this is the "gold standard" of astrological prediction. A true traditional astrological prediction must be made from a chart and the chart provided. The prediction needs to be in writing and give the astrological factors considered along with the analysis. The prediction needs to be made without knowing the outcome of the situation or the relevant life or event information for a natal chart. It needs to be as given to the client or as made in advance, without hindsight editing. And finally a true astrological prediction should show the results which should correspond to the analysis.
We need to be able to see how the astrologer did their work, step by step, so we can be sure of their astrological technique and that they even used astrology for their prediction. I do suffer by including the astrological factors because from time to time this either frightens or upsets clients because they can't understand the astrological terminology or clients decide that they don't like the outcome and want to argue with me about the technique used. I've never had anyone argue with me about the proper house rulership or aspects,etc. when they liked the outcome of the prediction! Still, only the foolish clients cause problems with this, many clients are very interested and appreciate seeing "under the hood" in the analysis and it is very useful for students and other astrologers to be able to see step by step how the analysis is made.
This "gold standard" of astrological analysis is pretty exacting. It eliminates all celebrity charts, looking at Hitler's and Einstein's chart, and going back and saying, "oh I can see why X happened, Lilith was sesquiqadrate your progessed Galactic Center".
It excludes, for example, Lilly's "prediction" of the Great Fire of London in 1666 as Lilly's prediction does not provide a chart and in fact, is not even astrological as it consists just of a picture of two men (Gemini. the sign of London) suspended over a fire. Also excluded is Zoller's "prediction" of 9/11. No chart is provided and the astrological factors used to make the reading are not provided.
I'm very cautious about public prediction, celebrities and flashy, topical readings. I just don't think I can do them accurately so I stay away from them. On the other hand, I do think it is important to push the envelope and see what can be done with traditional horary. While it took some time I just got feedback on a missing person horary I did awhile back. I wish I could give more information, but the client specifically requested that all identifying information be removed. Here is the chart, analysis and results.
It is my view that if we are going to advance as traditional astrologers that we need to stop fooling ourselves that we are predicting when we already know the outcome or when we are just guessing without actually using astrology. One of our goals in setting up the Society of Astrologers was to publish a journal. However, the submissions we got were 100% analyses made when the outcome was already known. This is not prediction!
When it comes to horary, I've published Warnock's Horary Case Book which contains over 40 real horary questions, as given to the client, the analyses, astrological factors considered and results.
In my courses, we work with charts whose outcome is unknown. This was particularly important to me in my Natal Astrology Course again no charts of Einstein, Hitler or Prince Charles.
Working with unknown charts and doing horary for clients puts your %$$ on the line! You will get it wrong on occasion. Looking at Hitler's chart you can never get it wrong, but then you never really are predicting.