### Description

Uses an Internet connection to download PISA data to a computer. Data come from the OECD website.

### Usage

downloadPISA(
root,
years = c(2000, 2003, 2006, 2009, 2012, 2015, 2018),
database = c("INT", "CBA", "FIN"),
cache = FALSE,
verbose = TRUE
)


### Arguments

 root a character string indicating the directory where the PISA data should be stored. Files are placed in a folder named PISA/[year]. years an integer vector of the assessment years to download. Valid years are 2000, 2003, 2006, 2009, 2012, 2015, and 2018. database a character vector to indicate which database to download from. For 2012, three databases are available (INT = International, CBA = Computer-Based Assessment, and FIN = Financial Literacy). For other years, only INT is available (for example, if PISA 2015 financial literacy is to be downloaded, the database argument should be set to INT). Defaults to INT. cache a logical value set to process and cache the text (.txt) version of files. This takes a very long time but saves time for future uses of the data. Default value is FALSE. verbose a logical value to either print or suppress status message output. The default value is TRUE.

### Details

The function uses download.file to download files from provided URLs. Some machines might require a different user agent in HTTP(S) requests. If the downloading gives an error or behaves unexpectedly (e.g., a zip file cannot be unzipped or a data file is significantly smaller than expected), users can toggle HTTPUserAgent options to find one that works for their machines. One common alternative option is

options(HTTPUserAgent="Mozilla/5.0 (Windows NT 6.1; WOW64; rv:53.0) Gecko/20100101 Firefox/53.0")

Beginning in the 2018 data files, the SPSS_STU_COG.zip source data file is a DEFLATE64 compressed zip file. This means that the user must manually extract the contained CY07_MSU_STU_COG.sav file using an external zip program capable of handling DEFLATE64 zip format, as existing R functions are unable to handle this zip format natively.

### Author(s)

Yuqi Liao, Paul Bailey, and Trang Nguyen

readPISA, download.file, options

### Examples

## Not run: