UPSC Prelims 2026 Question:

Which of the following statements with regard to Large Language Models (LLMs) used in machine learning  is/are correct? 

1. LLMs assign probabilities to the next possible words and then pick the one with the highest probability.
2. LLMs process data through mathematical optimization to minimise prediction errors.
3. LLMs produce unbiased outputs. 

Select the answer using the code given below: 

Answer: 2 

Explanation:  

Large Language Models are machine learning systems trained on very large text datasets to understand and  generate language-like outputs. They work by identifying statistical patterns in text and predicting likely sequences  of tokens. Their performance depends on training data, model architecture and optimisation, but their outputs are  not automatically neutral or bias-free.

• LLMs assign probabilities to possible next tokens based on the context provided. However, they  do not always simply pick the single highest-probability word, because generation may also involve  sampling methods, temperature, top-k or top-p selection. So, statement 1 is correct. 
• LLMs are trained through mathematical optimisation methods that adjust model parameters to reduce  prediction error. During training, the model compares predicted outputs with actual text patterns and  updates its internal weights to minimise loss. So, statement 2 is correct. 
• LLMs do not necessarily produce unbiased outputs. Their outputs may reflect biases present in training  data, model design, fine-tuning choices or user prompts. Therefore, they can generate biased, incomplete  or skewed responses. So, statement 3 is not correct. 

Therefore, option (2) is the correct answer.