diff --git a/_episodes/01-introduction.md b/_episodes/01-introduction.md
index f2cbb26..ba87e2d 100644
--- a/_episodes/01-introduction.md
+++ b/_episodes/01-introduction.md
@@ -90,7 +90,7 @@ When doing your mapping some required information may be missing. Below are the
 | Darwin Core Term | Definition | Comment | Example |
 |------------------|------------------------------------|---------------------------------------|-----------------|
 | [`occurrenceID`](https://dwc.tdwg.org/terms/#dwc:occurrenceID) | An identifier for the Occurrence (as opposed to a particular digital record of the occurrence). In the absence of a persistent global unique identifier, construct one from a combination of identifiers in the record that will most closely make the occurrenceID globally unique. | To construct a globally unique identifier for each occurrence you can usually concatenate station + date + scientific name (or something similar) but you'll need to check this is unique for each row in your data. It is preferred to use the fields that are least likely to change in the future for this. For ways to check the uniqueness of your occurrenceIDs see the [QA / QC]({{ page.root }}/06-qa-qc/index.html) section of the workshop. | Station_95_Date_09JAN1997:14:35:00.000_Atractosteus_spatula |
-| [`basisOfRecord`](https://dwc.tdwg.org/terms/#dwc:basisOfRecord) | The specific nature of the data record.  | Pick from these controlled vocabulary terms: [HumanObservation](http://rs.tdwg.org/dwc/terms/HumanObservation), [MachineObservation](http://rs.tdwg.org/dwc/terms/MachineObservation), [MaterialSample](http://rs.tdwg.org/dwc/terms/MaterialSample), [PreservedSpecimen](http://rs.tdwg.org/dwc/terms/PreservedSpecimen), [LivingSpecimen](http://rs.tdwg.org/dwc/terms/LivingSpecimen), [FossilSpecimen](http://rs.tdwg.org/dwc/terms/FossilSpecimen) | HumanObservation |
+| [`basisOfRecord`](https://dwc.tdwg.org/terms/#dwc:basisOfRecord) | The specific nature of the data record.  | Pick from these controlled vocabulary terms: [HumanObservation](http://rs.tdwg.org/dwc/terms/HumanObservation), [MachineObservation](http://rs.tdwg.org/dwc/terms/MachineObservation), [MaterialSample](http://rs.tdwg.org/dwc/terms/MaterialSample), [PreservedSpecimen](http://rs.tdwg.org/dwc/terms/PreservedSpecimen), [LivingSpecimen](http://rs.tdwg.org/dwc/terms/LivingSpecimen), [FossilSpecimen](http://rs.tdwg.org/dwc/terms/FossilSpecimen), [MaterialEntity](http://rs.tdwg.org/dwc/terms/MaterialEntity), [Event](http://rs.tdwg.org/dwc/terms/Event), [Taxon](http://rs.tdwg.org/dwc/terms/Taxon), [Occurrence](http://rs.tdwg.org/dwc/terms/Occurrence), [MaterialCitation](http://rs.tdwg.org/dwc/terms/MaterialCitation) | HumanObservation |
 | [`scientificName`](https://dwc.tdwg.org/terms/#dwc:scientificName) | The full scientific name, with authorship and date information if known. When forming part of an Identification, this should be the name in lowest level taxonomic rank that can be determined. This term should not contain identification qualifications, which should instead be supplied in the `identificationQualifier` term. | Note that cf., aff., etc. need to be parsed out to the `identificationQualifier` term. For a more thorough review of `identificationQualifier` see [this paper](https://doi.org/10.3389/fmars.2021.620702). | Atractosteus spatula |
 | [`scientificNameID`](https://dwc.tdwg.org/terms/#dwc:scientificNameID) | An identifier for the nomenclatural (not taxonomic) details of a scientific name. | Must be a WoRMS LSID for sharing to OBIS. Note that the numbers at the end are the AphiaID from WoRMS. | urn:lsid:marinespecies.org:taxname:218214 |
 | [`eventDate`](https://dwc.tdwg.org/terms/#dwc:eventDate) | The date-time or interval during which an Event occurred. For occurrences, this is the date-time when the event was recorded. Not suitable for a time in a geological context. | Must follow [ISO 8601](https://en.wikipedia.org/wiki/ISO_8601). See more information on dates in the [Data Cleaning]({{ page.root }}/03-data-cleaning/index.html) section of the workshop. | 2009-02-20T08:40Z |