Why does LLMS (AI) respond differently to the same query? | dhiraj k | September, 2025

Machine Learning


Have you ever asked a friend the same question in a short span just to receive two slightly different answers? Maybe you asked: “What should I eat for lunch?” And when they said it for the first time “pizza,” But I answered the second time “Let's go for the noodles.” They were confused and didn't change – it simply means that people consider multiple valid options and respond based on mood, context, or memory.

Large-scale language models (LLMs) such as ChatGpt, GPT-4, Claude, and DeepSeek behave surprisingly similarly. If you ask LLM for the same query multiple times, you may realize that you don't necessarily get the same answer. This can be frustrating, funny, or eye-opening. But behind this obvious contradiction is an interesting combination of probability, randomness, context windows and model design.

In this article, we will explore Why LLMS reacts differently to the same queryunlock the science behind it, share real-world analogies, write small Python examples and make sure this behavior is working.

The probabilistic brain of AI

It's different from a computer that always outputs 2 When asked “What is 1+1?”LLMS is a probability machine. They do not know the “truth” in human ways. Instead, it takes input and context into consideration to predict the next word (token) that is most likely.

For example, if you ask:

“The capital of France…”

The model may assign the following probabilities:

  • Paris → 0.97
  • Lyon → 0.01
  • Berlin → 0.01

By default, “Paris” is almost always present. However, if randomness is allowed (temperature > 0), you may see “Lyon” which is incorrect, but is statistically possible from the pattern of the data.

This is why you can get a slightly different answer to the same query. The model is essentially a “rolling dice” within the probability distribution each time.

Temperature and randomness

With LLMS, temperature It's like asking, “Do you want AI to be boring or creative?”

  • Temperature = 0 →Deterministic, almost always the same output.
  • Temperature = 1 → Balanced creativity and phrasing fluctuations.
  • Temperature> 1 →A very creative and sometimes pointless answer.

This explains why you might get a “summary list” when asked multiple times for the same model, and why you get a “long, narrative style explanation.”

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Master LLM and GEN AI with over 600 real interview questions
Master LLM and GEN AI with over 600 real interview questions

Context Impact

Imagine asking your friends:

  1. “What should I cook today?”
  2. “In fact, I want something soon.”

The second question is not independent. The first question changes.

Similarly, LLM considers that Context windowi.e. recent texts of conversation. Subtle differences in language, punctuation, or even previous exchanges can change the “mental state” of the model and affect the answer.

Where does randomness come from?

1. Sampling from a probability distribution

  • In its core, LLM generates the following words (tokens): Probability distribution About that vocabulary.
  • example:
  • “The capital of France…”
  • probability: Paris (0.92), Lyon (0.03), Berlin (0.01), ...
  • parable Paris It's the highest probability. Unless the model is always selected, the model is not always selected Temperature = 0 and TOP-K = 1 (Pure greedy decoding).
  • In temperature > 0 or sampling strategies (TOP-K, nucleus/TOP-P), randomness is explicitly injected.

2. RNG Generator (RNG)

  • When sampling a token, the model uses a Random Number Generator Decide Which word to choose? From the distribution.
  • Unless you fix it Random seeds,For each call to the model, a new random draw → various tokens may be selected.
  • That's why in the example code (transformers, OpenAI API), if you don't call something like that set_seed(42)gets different output for the same query.

3. Decoding strategy

LLM is more than just predicting a single token. They use Decoding algorithm Like:

  • Greedy decoding → Always select the top token (deterministic, no randomness).
  • TOP-K Sampling →Choose from the top k In most cases, the tokens will token randomly.
  • Nuclear Sampling (Top P) →Randomly select from the token to cumulative probability ≥ p.

Even at the same temperature, these strategies add variability unless they force deterministic greedy decoding.

4. Floating Points and Parallelism

  • In GPU/TPU, matrix operations may use non-deterministic floating-point kernels (due to optimization, parallelism, or hardware differences).
  • It could lead to this Small differences in probabilitythis can affect token sampling – especially when multiple tokens are probable.

Real-world analogy

Think of LLM as a Storyteller sitting on a campfire. If ten people ask the storyteller the same question, you might get 10 slightly different stories. Everything is rooted in truth, but seasoned with creativity, probability and memory.

Conclusion

Large language models don't give different answers because they are “confusing”. Because they are Probability-driven, context-sensitive, and creativity-enabled systems. Just like humans, they weigh multiple valid possibilities before speaking.

Sometimes we see small changes in language, changes in examples, and sometimes surprising, logical twists. Instead of being a flaw, this variability makes LLM more human-like, conversational and adaptive.

So, don't get frustrated the next time you ask the AI ​​the same question twice and realize another answer. You can see the beauty of probability, creativity and data diversity in the workplace. After all, life isn't boring if every storyteller always says it The exact same story?



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