index.Rmd

---
title       : What is data?
subtitle    : 
author      : Jeffrey Leek
job         : Johns Hopkins Bloomberg School of Public Health
logo        : bloomberg_shield.png
framework   : io2012        # {io2012, html5slides, shower, dzslides, ...}
highlighter : highlight.js  # {highlight.js, prettify, highlight}
hitheme     : tomorrow      # 
url:
  lib: ../../libraries
  assets: ../../assets
widgets     : [mathjax]            # {mathjax, quiz, bootstrap}
mode        : selfcontained # {standalone, draft}
---

```{r setup, cache = F, echo = F, message = F, warning = F, tidy = F}
# make this an external chunk that can be included in any file
options(width = 70)
opts_chunk$set(message = F, error = F, warning = F, echo = F, comment = NA, fig.align = 'center', dpi = 100, tidy = F, cache = T, cache.path = '.cache/', fig.path = 'fig/')

options(xtable.type = 'html')
knit_hooks$set(inline = function(x) {
  if(is.numeric(x)) {
    round(x, getOption('digits'))
  } else {
    paste(as.character(x), collapse = ', ')
  }
})
knit_hooks$set(plot = knitr:::hook_plot_html)
```


## Definition of data

<q>Data are values of qualitative or quantitative variables, belonging to a set of items.</q>

[http://en.wikipedia.org/wiki/Data](http://en.wikipedia.org/wiki/Data)


---

## Definition of data
<q>Data are values of qualitative or quantitative variables, belonging to a <redtext>set of items</redtext>.</q>

[http://en.wikipedia.org/wiki/Data](http://en.wikipedia.org/wiki/Data)

__Set of items__: Sometimes called the population; the set of objects you are interested in



---

## Definition of data
<q>Data are values of qualitative or quantitative <redtext>variables</redtext>, belonging to a set of items.</q>

[http://en.wikipedia.org/wiki/Data](http://en.wikipedia.org/wiki/Data)

__Variables__: A measurement or characteristic of an item.


---

## Definition of data
<q>Data are values of <redtext>qualitative</redtext> or <redtext>quantitative</redtext> variables, belonging to a set of items.</q>

[http://en.wikipedia.org/wiki/Data](http://en.wikipedia.org/wiki/Data)


__Qualitative__: Country of origin, sex, treatment

__Quantitative__: Height, weight, blood pressure


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## What do data look like? 

<img class=center src="../../assets/img/01_DataScientistToolbox/fastq.png" height=400 />

[http://brianknaus.com/software/srtoolbox/s_4_1_sequence80.txt](http://brianknaus.com/software/srtoolbox/s_4_1_sequence80.txt)

---

## What do data look like? 

<img class=center src="../../assets/img/01_DataScientistToolbox/twitter.png" height=400 />

[https://dev.twitter.com/docs/api/1/get/blocks/blocking](https://dev.twitter.com/docs/api/1/get/blocks/blocking)

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## What do data look like? 

<img class=center src="../../assets/img/01_DataScientistToolbox/medicalrecord.png" height=400 />


[http://blue-button.github.com/challenge/](http://blue-button.github.com/challenge/)

---

## What do data look like?

<img class=center src="../../assets/img/01_DataScientistToolbox/deepcat.jpg" height=400 />

[http://www.nytimes.com/2012/06/26/technology/in-a-big-network-of-computers-evidence-of-machine-learning.html?pagewanted=all&_r=0](http://www.nytimes.com/2012/06/26/technology/in-a-big-network-of-computers-evidence-of-machine-learning.html?pagewanted=all&_r=0)


---

## What do data look like?

<img class=center src="../../assets/img/01_DataScientistToolbox/darwintunes.png" height=400 />


[http://www.pnas.org/content/109/30/12081.full](http://www.pnas.org/content/109/30/12081.full)
[https://soundcloud.com/uncoolbob/sets/darwintunes](https://soundcloud.com/uncoolbob/sets/darwintunes)

---

## What do data look like? 

<img class=center src="../../assets/img/01_DataScientistToolbox/datagov.png" height=400 />


[http://www.data.gov/](http://www.data.gov/)

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## What do data look like? Rarely

<img class=center src="../../assets/img/01_DataScientistToolbox/excel.png" height=400 />




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## The data is the second most important thing

* The most important thing in data science is the question
* The second most important is the data
* Often the data will limit or enable the questions
* But having data can't save you if you don't have a question