Wanted your thougts if i understand this correctly - Conservatism bias is paying too much emphasis to the old information and not incorporating the new information appropriately and Representative bias is the opposite where the new information is given over-emphasis.
In an ideal world, it would be best to be somewhere in-between. Is this a right approach?
best approach in either case - get all the facts, make your decision based on the facts.
gather the information completely. make your decision purely based on the facts and analysis. If the facts and subsequent analysis tell you to use the old information - go that way. If it tells you to base your information on the new information - then go that way. Do not be biased in either direction, without appropriate and complete analysis. Further once you have done your analysis - document the facts, analysis and the information in your notes - so you have the relevant information for future use.