He most serious cause of forecasting errors is the assumptions held by the forecaster.
"a reading of history shows that the most serious [forecasting] errors are the result of mistaken assumptions. which shall we choose as an example? the patent official who forecast the decline in invention around the [previous] turn of the century? the physicist who said heavier than air flight was impossible? the office equipment executive who saw no need for more than six computers worldwide? the list goes on. forecasters had all the information in front of them. their interpretation of what the information meant caused the problem. it's not what we don't know that's the problem; it's what we think we know and don't." p. bishop
identify one of your assumptions and write a short paragraph on why this assumption could cause you to err on a forecast. examples could be assumption that the technology will progress, assumption that conflict will start (or stop), assumption that western values are applicable in eastern cultures,