TASK DEFINITION: In this task, you are given a paragraph (from a research paper) and your task is to classify each sentence of the paragraph (assume n sentence) into the following categories: Background, Purpose, Method, Finding/Contribution, or Other. Return the output in this format: 1 - category of sentence 1, 2 - category of sentence 2, ..., n - category of sentence n; where each number indicates the order of the sentence. The categories can be identified using the following questions: 
 Background: - Why is this problem important? - What relevant works have been done before? - What did the previous works miss? - What are the high-level research questions? - How might this help other researchers?
 Purpose: - What specific things do the researchers want to do? - What specific knowledge do the researchers want to know? - What specific hypothesis do the researchers want to test?
 Method: - How did the researchers do it or find it out? - What are the procedures and steps of this research?
 Finding/Contribution: - What did the researchers find out? Did the proposed methods work? - Did things behave as the researchers expected?
Other: put every text fragment that does not fit into any of the categories above here. Put a sentence here if its not in English, is not part of the article, contains numbers and dates, is a caption of a figure or a table, is a formatting error, or you are not sure about it.
PROBLEM: Statistics. Statistical analyses were conducted using SPSS software (version 20 SPSS, Inc., Chicago, IL). For normally distributed variables, Student's t-test and one-way ANOVA were used for comparisons, and the data are presented as the mean ± SE. The Mann-Whitney U and Kruskal-Wallis tests were used for comparisons of variables that were not normally distributed. Correlations were assessed with Pearson's correlation coefficient for parametric distributions. Statistical significance was set at P < 0.05.

SOLUTION: 1 - method, 2 - method, 3 - method, 4 - method, 5 - finding, 6 - finding, 7 - finding

PROBLEM: This is the eighth article in our series on the history of pediatric specialties. Dr. Shulman describes the history of infectious diseases over the centuries. Many of these major killers of children were conquered by research that led to understanding the causes of these diseases and eventually to establishing means of prevention and treatment. Dr. Shulman also describes the organizations and publications that have furthered the development of treatment, research and education in this specialty. The future of this field includes the challenges of understanding and treating infectious diseases in immunocompromised children and in developing countries where infectious disease is still a major killer.

SOLUTION: 1 - background, 2 - purpose, 3 - background, 4 - purpose, 5 - purpose, 6 - finding

PROBLEM: The number in square brackets following a selected paper, e.g. [7], refers to its number in the annotated references of the corresponding review.

SOLUTION:
1 - method, 2 - method