自然言語処理（NLP）テスト

You are working on a project to detect hate speech in social media posts. Your initial model, a basic binary classification model, has achieved high accuracy during training, but it's not performing well on the validation set. You also notice that your dataset has significantly more non-hate-speech examples than hate-speech examples. Given this situation, which of the following strategies could likely improve the performance of your model?

A: Collect more data and retrain the model.
B: Introduce data augmentation techniques specifically for hate-speech examples.
C: Change the model architecture from binary classification to multi-class classification.
D: Replace all the words in the posts with their synonyms to increase the diversity of the data.
E: Remove the non-hate-speech examples from the dataset to focus on the hate-speech examples.

You are a data scientist at an online marketplace company. Your task is to develop a solution to identify fake reviews on your platform. You have a dataset where each review is marked as either 'genuine' or 'fake'. After developing an initial model, you find that it's accurately classifying 'genuine' reviews but performing poorly with 'fake' ones. Which of the following steps can likely improve your model's performance in this context?

A: Use a more complex model to capture the intricacies of 'fake' reviews.
B: Obtain more data to improve the overall performance of the model.
C: Implement a cost-sensitive learning approach, placing a higher penalty on misclassifying 'fake' reviews.
D: Translate the reviews to another language and then back to the original language to enhance their clarity.
E: Remove the 'genuine' reviews from your training set to focus on 'fake' reviews.

Consider the following pseudo code for calculating the probability of a sentence using a bigram language model:

Assume that the bigram and unigram counts are as follows:

bigram_counts = {("i", "like"): 2, ("like", "cats"): 1, ("cats", "too"): 1}
unigram_counts = {"i": 2, "like": 2, "cats": 2, "too": 1}
vocabulary_size = 4

What is the probability of the sentence "I like cats too" using the bigram language model?

You are working on a natural language processing project and need to preprocess the text data for further analysis. Your task is to tokenize the text and apply stemming to the tokens. Assuming you have an English text corpus, which of the following combinations of tokenizer and stemmer would most likely result in the best balance between token granularity and generalization?

You have been provided with a pre-trained BERT model (pretrained_bert_model) and you need to perform Word Sense Disambiguation (WSD) on the word "bat" in the following sentence:

"The bat flew around the room."

You have also been provided with a function called cosine_similarity(vec1, vec2) that calculates the cosine similarity between two vectors.

Which of the following steps should you perform to disambiguate the word "bat" in the given sentence using the BERT model and cosine similarity?

1. Tokenize the sentence and pass it through the pre-trained BERT model.
2. Extract the embeddings of the word "bat" from the sentence.
3. Calculate the cosine similarity between the "bat" embeddings and each sense's representative words.
4. Choose the sense with the highest cosine similarity.
5. Calculate the Euclidean distance between the "bat" embeddings and each sense's representative words.
6. Choose the sense with the lowest Euclidean distance.