MLS-C01 Question Bank · Latest 50 Questions Free Preview (Page 3/5)
Questions 21–30 of the latest 50 MLS-C01 questions (5 pages total), with answers and explanations, no login required. Practice all 380 questions online.
Question 21 · No. 351 · Single choice
A company distributes an online multiple-choice survey to several thousand people. Respondents to the survey can select multiple options for each question. A machine learning (ML) engineer needs to comprehensively represent every response from all respondents in a dataset. The ML engineer will use the dataset to train a logistic regression model. Which solution will meet these requirements?
- A. Perform one-hot encoding on every possible option for each question of the survey.
- B. Perform binning on all the answers each respondent selected for each question.
- C. Use Amazon Mechanical Turk to create categorical labels for each set of possible responses.
- D. Use Amazon Textract to create numeric features for each set of possible responses.
Answer: A
Explanation: 这个情况需要对每个问题的所有可能选项进行编码,以便能够综合代表所有回应者的每一个回答。使用 one-hot 编码(选项 A)是一种有效的处理多选题的方法,因为它可以为每个可能的答案创建一个二进制特征,同时不会引入额外的维度。这种编码方式适用于分类问题,并且在训练机器学习模型时,如逻辑回归模型,它能够正确地处理多个类别选项。因此,选项 B、C 和 D 都不能满足题干中提到的需要综合所有回答者的所有响应的要求。
Question 22 · No. 352 · Multiple choice
A machine learning (ML) specialist is developing a model for a company. The model will classify and predict sequences of objects that are displayed in a video. The ML specialist decides to use a hybrid architecture that consists of a convolutional neural network (CNN) followed by a classifier three-layer recurrent neural network (RNN). The company developed a similar model previously but trained the model to classify a different set of objects. The ML specialist wants to save time by using the previously trained model and adapting the model for the current use case and set of objects. Which combination of steps will accomplish this goal with the LEAST amount of effort? (Choose two.)
- A. Reinitialize the weights of the entire CNN. Retrain the CNN on the classification task by using the new set of objects.
- B. Reinitialize the weights of the entire network. Retrain the entire network on the prediction task by using the new set of objects.
- C. Reinitialize the weights of the entire RNN. Retrain the entire model on the prediction task by using the new set of objects.
- D. Reinitialize the weights of the last fully connected layer of the CNN. Retrain the CNN on the classification task by using the new set of objects.
- E. Reinitialize the weights of the last layer of the RNN. Retrain the entire model on the prediction task by using the new set of objects.
Answer: D, E
Explanation: 在选择正确答案时,我们需要考虑如何在最小的开销下适应新的对象分类任务。选项 D 和 E 都涉及对网络中最后一个关键层(即 CNN 的最后一层和 RNN 的最后一层)的权重初始化重新设置,并通过使用新的对象集训练整个模型来完成预测任务。这种策略可以在保留原有模型结构的同时,最小化对新任务的训练时间。
Question 23 · No. 353 · Multiple choice
A data scientist is building a new model for an ecommerce company. The model will predict how many minutes it will take to deliver a package. During model training, the data scientist needs to evaluate model performance. Which metrics should the data scientist use to meet this requirement? (Choose two.)
- A. InferenceLatency
- B. Mean squared error (MSE)
- C. Root mean squared error (RMSE)
- D. Precision
- E. Accuracy
Answer: B, C
Explanation: 在模型训练期间,数据科学家需要评估模型性能。在这种情况下,他们应该使用能够提供关于预测质量的信息的指标。均方误差(MSE)和根均方误差(RMSE)都是衡量预测与实际值之间差异的度量,因此对于评估预测时间准确性非常有用。而推理延迟(InferenceLatency)是与预测计算速度相关的指标,精度(Precision)和准确率(Accuracy)通常用于分类问题,而不是回归问题(如预测时间)。
Question 24 · No. 354 · Single choice
A data scientist uses Amazon SageMaker Data Wrangler to obtain a feature summary from a dataset that the data scientist imported from Amazon S3. The data scientist notices that the prediction power for a dataset feature has a score of 1. What is the cause of the score?
- A. Target leakage occurred in the imported dataset.
- B. The data scientist did not fine-tune the training and validation split.
- C. The SageMaker Data Wrangler algorithm that the data scientist used did not find an optimal model fit for each feature to calculate the prediction power.
- D. The data scientist did not process the features enough to accurately calculate prediction power.
Answer: A
Question 25 · No. 355 · Single choice
A company’s machine learning (ML) team needs to build a system that can detect whether people in a collection of images are wearing the company’s logo. The company has a set of labeled training data. Which algorithm should the ML team use to meet this requirement?
- A. Principal component analysis (PCA)
- B. Recurrent neural network (RNN)
- C. К-nearest neighbors (k-NN)
- D. Convolutional neural network (CNN)
Answer: D
Explanation: 考虑到任务是识别图像中的人物是否穿着公司的Logo,这涉及到图像分类问题。在给定的选项中,以下算法最适合用于解决这个问题: A. 主成分分析(PCA):主要用于降维和数据可视化,对于图像分类任务效果不佳。 B. 循环神经网络(RNN):主要用于处理序列数据,如文本或时间序列数据,对于图像识别任务效率较低。 C. k-近邻算法(k-NN):基于距离度量进行分类,不适用于复杂的图像识别任务。 D. 卷积神经网络(CNN):专门设计用于处理图像、视频等二维数据,通过卷积层和池化层有效地提取特征,非常适合图像分类任务。
Question 26 · No. 356 · Multiple choice
A company wants to use machine learning (ML) to improve its customer churn prediction model. The company stores data in an Amazon Redshift data warehouse. A data science team wants to use Amazon Redshift machine learning (Amazon Redshift ML) to build a model and run predictions for new data directly within the data warehouse. Which combination of steps should the company take to use Amazon Redshift ML to meet these requirements? (Choose three.)
- A. Define the feature variables and target variable for the churn prediction model.
- B. Use the SOL EXPLAIN_MODEL function to run predictions.
- C. Write a CREATE MODEL SQL statement to create a model.
- D. Use Amazon Redshift Spectrum to train the model.
- E. Manually export the training data to Amazon S3.
- F. Use the SQL prediction function to run predictions.
Answer: A, C, F
Explanation: 根据提供的问题,公司需要使用机器学习(ML)来改进客户流失预测模型,并且数据存储在Amazon Redshift数据仓库中。公司想要通过Amazon Redshift ML在数据仓库内部直接构建模型和对新数据进行预测。以下是应该采取的步骤组合: 1. **定义特征变量和目标变量**:这是创建预测模型的第一步,即确定哪些数据可以用来预测客户是否会流失。 2. **编写CREATE_MODEL SQL语句来创建模型**:这涉及到通过特定的SQL命令在Amazon Redshift中创建机器学习模型。 3. **使用SQL预测函数运行预测**:这是使用Amazon Redshift ML功能来对新数据进行预测的方法之一。 4. **使用Amazon Redshift Spectrum进行模型训练**:虽然这是一个可能的选项,但题目中并未提供足够的信息来选择这个步骤作为公司需要采取的措施。 5. **手动将训练数据导出到Amazon S3**:这是将数据从Amazon Redshift移动到Amazon S3的过程,但这不是在数据仓库内部直接预测的必要步骤。 6. **使用SOL EXPLAIN_MODEL函数来运行预测**:这个选项可能与实际使用Amazon Redshift ML的方法不符,通常不会用到此功能来进行预测。 因此,根据问题的要求和上下文,选择的正确步骤组合是A、C和F。
Question 27 · No. 357 · Single choice
A company is building a predictive maintenance system using real-time data from devices on remote sites. There is no AWS Direct Connect connection or VPN connection between the sites and the company's VPC. The data needs to be ingested in real time from the devices into Amazon S3. Transformation is needed to convert the raw data into clean .csv data to be fed into the machine learning (ML) model. The transformation needs to happen during the ingestion process. When transformation fails, the records need to be stored in a specific location in Amazon S3 for human review. The raw data before transformation also needs to be stored in Amazon S3. How should an ML specialist architect the solution to meet these requirements with the LEAST effort?
- A. Use Amazon Data Firehose with Amazon S3 as the destination. Configure Firehose to invoke an AWS Lambda function for data transformation. Enable source record backup on Firehose.
- B. Use Amazon Managed Streaming for Apache Kafka. Set up workers in Amazon Elastic Container Service (Amazon ECS) to move data from Kafka brokers to Amazon S3 while transforming it. Configure workers to store raw and unsuccessfully transformed data in different S3 buckets.
- C. Use Amazon Data Firehose with Amazon S3 as the destination. Configure Firehose to invoke an Apache Spark job in AWS Glue for data transformation. Enable source record backup and configure the error prefix.
- D. Use Amazon Kinesis Data Streams in front of Amazon Data Firehose. Use Kinesis Data Streams with AWS Lambda to store raw data in Amazon S3. Configure Firehose to invoke a Lambda function for data transformation with Amazon S3 as the destination.
Answer: A
Explanation: 选项A使用Amazon Data Firehose作为目的地与Amazon S3。配置Firehose调用AWS Lambda函数进行数据转换,并在Firehose上启用源记录备份。这种方案能够实时将设备数据导入到Amazon S3,期间进行数据转换,当转换失败时,可以将记录存储在特定的Amazon S3位置供人工审查,同时也存储原始数据在Amazon S3中。它满足了所有的需求且操作最少。
Question 28 · No. 358 · Single choice
A machine learning (ML) specialist collected daily product usage data for a group of customers. The ML specialist appended customer metadata such as age and gender from an external data source. The ML specialist wants to understand product usage patterns for each day of the week for customers in specific age groups. The ML specialist creates two categorical features named dayofweek and binned_age, respectively. Which approach should the ML specialist use discover the relationship between the two new categorical features?
- A. Create a scatterplot for day_of_week and binned_age.
- B. Create crosstabs for day_of_week and binned_age.
- C. Create word clouds for day_of_week and binned_age.
- D. Create a boxplot for day_of_week and binned_age.
Answer: B
Explanation: 根据题干描述,机器学习专家希望理解每周每一天的产品使用模式,以及特定年龄组的客户。对于两个新的分类特征 dayofweek 和 binned_age,我们需要分析它们之间的关系。在这些选项中,创建交叉表(crosstabs)对于分析分类变量之间的关系最为合适。交叉表能够显示不同类别组合的频率或计数,从而帮助我们发现 dayofweek 和 binned_age 之间的关联性。
Question 29 · No. 359 · Single choice
An ecommerce company discovers that the search tool for the company's website is not presenting the top search results to customers. The company needs to resolve the issue so the search tool will present results that customers are most likely to want to purchase. Which solution will meet this requirement with the LEAST operational effort?
- A. Use the Amazon SageMaker BlazingText algorithm to add context to search results through query expansion.
- B. Use the Amazon SageMaker XGBoost algorithm to improve candidate ranking.
- C. Use Amazon CloudSearch and sort results by the search relevance score.
- D. Use Amazon CloudSearch and sort results by the geographic location.
Answer: C
Explanation: Amazon CloudSearch 是一个高度可扩展的搜索服务,允许您将快速、相关和自定义的搜索体验添加到您的 Web、移动或任何应用程序中。在这种情况下,为了提供最相关的搜索结果以满足顾客的需求,使用 Amazon CloudSearch 并根据搜索相关性分数对结果进行排序是最佳选择。这将确保顾客得到他们最有可能购买的产品。这种方法需要最少的操作努力,因为它不需要额外的复杂算法来调整查询或考虑地理位置等非相关因素。
Question 30 · No. 360 · Single choice
A machine learning (ML) engineer is creating a binary classification model. The ML engineer will use the model in a highly sensitive environment. There is no cost associated with missing a positive label. However, the cost of making a false positive inference is extremely high. What is the most important metric to optimize the model for in this scenario?
- A. Accuracy
- B. Precision
- C. Recall
- D. F1
Answer: B
Explanation: 在这个场景中,最关注的是避免假阳性错误的代价非常高。这意味着我们更关心模型正确识别阳性标签的能力,即使这意味着可能会有少量的阴性标签被误判为阳性。因此,选择精确度(Precision)作为优化模型的最重要指标更为合适。