10 February 2021

Goals for today

  • Understand the concept of metadata
  • Understand the different kinds of metadata
  • Get an introduction to the Ecological Metadata Language

What is metadata?

Definition

“data that provides information about other data”

What is metadata?

Definition

“shorthand representation of the data to which they refer”

Metadata is everywhere

Book

  • title
  • author
  • publisher
  • copyright
  • table of contents / index

Metadata is everywhere

Phone calls

  • number called or received from
  • time initiated & ended
  • location of callers

Metadata is everywhere

Email

  • subject
  • from
  • to
  • date & time sent
  • sending & receiving IP addresses

Benefits of metadata

Metadata benefits science by

  1. increased data longevity

    • long-term studies outlast investigators/students
    • many scientists contribute info from many areas

Benefits of metadata

Metadata benefits science by

  1. increased data longevity

  2. increased data reuse & sharing

    • info helps others know if/how they could them
    • facilitates meta-analyses

Benefits of metadata

Metadata benefits science by

  1. increased data longevity

  2. increased data reuse & sharing

  3. expanded scales/scopes of analyses

    • short-term evolve into long-term
    • facilitates creativity

Kinds of metadata

Descriptive

Descriptive metadata is information about a resource that is used for searching & identification

  • title
  • abstract
  • author
  • keywords

Kinds of metadata

Structural

Structural metadata indicates how 2+ objects are connected

  • tables
  • fields
  • keys
  • relationships

Entity–relationship model

Structural metadata are often conceptualized in an entity–relationship model

Entity–relationship model

Entity

An entity can be physical or logical

  • physical entities actually exist (eg, lake, fish)
  • logical entities could exist (eg, a sampling event)
  • entities have attributes (eg, depth, mass, date)

Entity–relationship model

Relationship

Entities are connected via a relationship

  • relationships can be thought of as verbs
  • Sarah supervises Mark
  • Omar samples Lake Washington

Entity–relationship diagram

ER models are usually drawn as boxes (entities) connected by lines (relationships)

Entity–relationship diagram

Entity–relationship diagram

Kinds of metadata

Administrative

Administrative metadata refers to technical info about a data file

  • file type (eg, .csv)
  • when the file was created
  • how the file was created

Administrative metadata

Rights management

  • Who has had custody/ownership of the data?
  • What intellectual property rights must be observed?

Administrative metadata

Preservation

  • Where are the data stored?
  • How are they identified (eg, digitial object identifier)?

Kinds of metadata

Reference

Information about the contents and quality of statistical data

  • description of fields
  • QA/QC

Kinds of metadata

Process

Describes the collection and any processing of the data

  • raw vs cleaned
  • reproducible workflows

Process metadata

Michener (2005)

Kinds of metadata

Accessibility

Information about improved access to data

  • audio transcripts
  • alternate text for an image
  • large print

Section 508

How much metadata is enough?

Two factors to consider

  1. effort involved in creating the metadata

  2. value derived from it

In general, assume that “more is better”

No metadata

Minimal metadata

Extensive

Ecological Metadata Language

Ecological Metadata Language

Fegraus et al (2005)

EML describes a range of essential aspects of ecological data

  • names & definitions of variables
  • units of measurement
  • date/time/location of data collection
  • identity/contact for individual who collected the data
  • sampling design

Ecological Metadata Language

Fegraus et al (2005)

EML reduces ambiguity & uncertainty by formalizing metadata concepts

  • uses comprehensive and standardized set of terms
  • uses definitions intended specifically for ecological data

Ecological Metadata Language

Categories

  1. General dataset

  2. Geographic

  3. Temporal

  4. Taxonomic

  5. Methods

  6. Data table

Ecological Metadata Language

General dataset

Contains concepts that

  • identify and name the dataset
  • describe the purpose of the data collection
  • describe the questions the data were intended to address

General

Ecological Metadata Language

Geographic

Contains information about where

  • the research project took place
  • the samples were collected
  • spatial or geographic references (UTM, lat/lon)

Geographic

Ecological Metadata Language

Temporal

Contains information about when

  • range of dates (monthly between June 2019 and Dec 2020)
  • specific time periods (01 May 2019, 08:00–12:00)
  • gaps in time (no data from July 2020 because of power loss)

Temporal

Ecological Metadata Language

Taxonomic

Contains information about

  • taxonomic authority (book or system used to identify species)
  • taxonomic rank (family, genus, species)

Taxonomic

Ecological Metadata Language

Methods

Contains information about what happened

  • instruments or devices used to collect data
  • protocols
  • units of the samples

Ecological Metadata Language

Methods

Contains information about what happened

  • instruments or devices used to collect data
  • protocols
  • units of the samples

Unlike the Methods section of a publication, fully detailed descriptions can be included

Methods

Ecological Metadata Language

Data table

Contains information about a rectangular table

  • file name
  • number of records
  • structure of the table (attributes of fields/columns)

Ecological Metadata Language

Data table

  • name is a unique name for the field/column (date)
  • label describes the field/column ("date of sample collection)
  • definition indicates what the values represent (length of a fish)
  • units (grams, meters)
  • type (numeric, character)
  • precision (mm)
  • attribute domain description defines codes & domain of values
  • BVA = Bear Valley Creek
  • Length is a positive, real value

Data table

 

Knowledge Network for Biocomplexity

The KNB is an international repository intended to facilitate ecological & environmental research

  • you can upload/publish data with a DOI
  • you can write EML

{dataone} package

Provides read & write access to data and metadata from DataONE network

  • KNB Data Repository
  • Dryad
  • NEON
  • USGS
  • NOAA

{EML} package

## username
me <- list(individualName = list(givenName = "Mark",
                                 surName = "Scheuerell"))

## list of attributes
my_eml <- list(
  dataset = list(
    title = "A Minimal Valid EML Dataset",
    creator = me,
    contact = me
  )
)

## inspect the EML
my_eml

{EML} output

$dataset
$dataset$title
[1] "A Minimal Valid EML Dataset"

$dataset$creator
$dataset$creator$individualName
$dataset$creator$individualName$givenName
[1] "Mark"

$dataset$creator$individualName$surName
[1] "Scheuerell"



$dataset$contact
$dataset$contact$individualName
$dataset$contact$individualName$givenName
[1] "Mark"

$dataset$contact$individualName$surName
[1] "Scheuerell"

What’s next?

We’ll discuss data analysis and visualization