Why hallucinations happen
Language models work by predicting the most statistically likely continuation of text. When your prompt is vague or underspecified, the model has little to anchor its response to. Rather than stopping to ask for clarification, it fills in the blanks — drawing on patterns from its training data that may have nothing to do with your actual intent. The result is a response that sounds confident and coherent but may contain:- Facts that were never true
- Dates, names, or figures that are plausible but wrong
- Advice that doesn’t apply to your specific situation
- References to sources that don’t exist
How your prompt contributes to hallucination risk
Three prompt characteristics are most strongly correlated with hallucination: Vague scope. When you ask the model to “tell me about” something without specifying what aspect, depth, or purpose, it decides on your behalf — and its choice may not match yours. Missing context. The model doesn’t know who you are, what you already know, or what you’re trying to accomplish. Without that context, it makes assumptions, and those assumptions can be wrong. No output constraints. When you don’t specify a format, length, or structure, the model picks one. A loosely constrained prompt often leads to a loosely constrained response — one that wanders away from the specific information you needed.The spectrum: not all hallucinations are equal
Hallucination is not a single type of failure. You are more likely to catch and correct it if you know what form it takes:- Factual errors — the model states something objectively false (a wrong date, a misattributed quote, a made-up statistic)
- Off-topic responses — the model answers a question you didn’t ask because your prompt was ambiguous about which question you meant
- Format issues — the model structures its response in a way that obscures key information or invents structure that wasn’t requested
How S.I.M.P. addresses this
S.I.M.P. analyzes your prompt across four dimensions: missing context, vague scope, ambiguous language, and missing output constraints. It assigns a risk score from 1 to 10 and a label — Low, Moderate, High, or Critical — based on how many of these problems are present and how severe they are. After scoring, S.I.M.P. rewrites your prompt into a sanitized version and shows you exactly what changed and why, so you can understand what made the original risky and apply the same thinking to future prompts.No tool can eliminate hallucination entirely. S.I.M.P. reduces risk by making your prompt as unambiguous as possible.