SAQA All qualifications and part qualifications registered on the National Qualifications Framework are public property. Thus the only payment that can be made for them is for service and reproduction. It is illegal to sell this material for profit. If the material is reproduced or quoted, the South African Qualifications Authority (SAQA) should be acknowledged as the source.
SOUTH AFRICAN QUALIFICATIONS AUTHORITY 
REGISTERED UNIT STANDARD: 

Understand and manage spatial data errors 
SAQA US ID UNIT STANDARD TITLE
258778  Understand and manage spatial data errors 
ORIGINATOR
SGB Geographical Information Sciences 
PRIMARY OR DELEGATED QUALITY ASSURANCE FUNCTIONARY
-  
FIELD SUBFIELD
Field 12 - Physical Planning and Construction Physical Planning, Design and Management 
ABET BAND UNIT STANDARD TYPE PRE-2009 NQF LEVEL NQF LEVEL CREDITS
Undefined  Regular  Level 6  Level TBA: Pre-2009 was L6 
REGISTRATION STATUS REGISTRATION START DATE REGISTRATION END DATE SAQA DECISION NUMBER
Reregistered  2015-07-01  2018-06-30  SAQA 10105/14 
LAST DATE FOR ENROLMENT LAST DATE FOR ACHIEVEMENT
2019-06-30   2022-06-30  

In all of the tables in this document, both the pre-2009 NQF Level and the NQF Level is shown. In the text (purpose statements, qualification rules, etc), any references to NQF Levels are to the pre-2009 levels unless specifically stated otherwise.  

This unit standard does not replace any other unit standard and is not replaced by any other unit standard. 

PURPOSE OF THE UNIT STANDARD 
This unit standard is useful for people who aim to achieve career advancement in the GIS field and provides them with essential knowledge about handling spatial data errors.

A person credited with this unit standard is able to:
  • Identify and manage positional measurement errors in spatial data.
  • Identify and manage attribute errors in spatial data.
  • Identify and manage compilation errors in spatial data.
  • Identify and manage processing errors in spatial data.

    Specific range statements are provided in the body of the unit standard where they apply to particular specific outcomes or assessment criteria. 

  • LEARNING ASSUMED TO BE IN PLACE AND RECOGNITION OF PRIOR LEARNING 
    The credit calculation is based on the assumption that learners are already competent in terms of the following outcomes or areas of learning when starting to learn towards this unit standard:
  • Communication at NQF Level 5.
  • Mathematical Literacy at NQF Level 5.
  • Demonstrate a thorough knowledge of GPS technology.
  • Use field data capture devices.
  • Plan and check the capture of Geo-information from secondary data sources.
  • Facilitate fieldwork activities.
  • Demonstrate a capability of visual image interpretation of the real world. 

  • UNIT STANDARD RANGE 
    N/A 

    Specific Outcomes and Assessment Criteria: 

    SPECIFIC OUTCOME 1 
    Identify and manage positional measurement errors in spatial data. 

    ASSESSMENT CRITERIA
     

    ASSESSMENT CRITERION 1 
    Geodetic Control and GPS errors are identified and reported in accordance with the appropriate national and international standards. 

    ASSESSMENT CRITERION 2 
    Errors from interpretation of remotely sensed imagery are identified and reported on in the context of the source of the data/imagery used. 

    ASSESSMENT CRITERION 3 
    Survey description errors are identified and reported on in the context of the survey technology, instruments and procedures used. 
    ASSESSMENT CRITERION RANGE 
    Including but not limited to descriptions including uncertain boundaries (E.g. Centre of a river), missing beacons and displaced beacons.
     

    ASSESSMENT CRITERION 4 
    Digitizing errors are identified and reported on in the context of the equipment and procedures used. 

    ASSESSMENT CRITERION 5 
    Transformation errors are identified and reported on in the context of the mathematical procedures used. 

    ASSESSMENT CRITERION 6 
    Positional measurement errors that can be corrected are identified and corrected in compliance with best practice and procedures used in a GIS environment. 
    ASSESSMENT CRITERION RANGE 
    Including but not limited to:
  • Overshoots, undershoots, sliver polygon, open polygon, and transposed co-ordinates.
     

  • SPECIFIC OUTCOME 2 
    Identify and manage attribute errors in spatial data used in a GIS. 

    ASSESSMENT CRITERIA
     

    ASSESSMENT CRITERION 1 
    Statistical under and over counts are identified and reported. 

    ASSESSMENT CRITERION 2 
    Operator errors are identified and reported. 
    ASSESSMENT CRITERION RANGE 
    Including but not limited to:
  • Typing errors and misinterpretation errors.
     

  • ASSESSMENT CRITERION 3 
    Fieldwork ambiguities or design errors are identified and reported. 

    ASSESSMENT CRITERION 4 
    Attribute errors that can be corrected are identified and corrected. 
    ASSESSMENT CRITERION RANGE 
    Including but not limited to:
  • Missing IDs, duplicated IDs, and spelling errors.
     

  • SPECIFIC OUTCOME 3 
    Identify and manage compilation errors in spatial data used in a GIS environment. 

    ASSESSMENT CRITERIA
     

    ASSESSMENT CRITERION 1 
    Data assemblage errors are identified and reported in the context of the GIS project. 
    ASSESSMENT CRITERION RANGE 
    Aggregation, Disaggregating.
     

    ASSESSMENT CRITERION 2 
    Generalisation errors are identified and reported in the context of the GIS project. 

    ASSESSMENT CRITERION 3 
    Displacement errors are identified and reported in the context of the GIS project. 
    ASSESSMENT CRITERION RANGE 
    E.g. When a road and river runs in close proximity, one may be displaced when captured.
     

    ASSESSMENT CRITERION 4 
    Compilation errors are identified and reported on in the context of the GIS project. 
    ASSESSMENT CRITERION RANGE 
    Giving preference to the data source of higher authority.
     

    SPECIFIC OUTCOME 4 
    Identify and manage processing errors in spatial data used in a GIS project. 

    ASSESSMENT CRITERIA
     

    ASSESSMENT CRITERION 1 
    Errors due to incorrect interpretation of the process instructions are identified and reported. 

    ASSESSMENT CRITERION 2 
    Calculation errors are identified and reported in the context of the following range statement. 
    ASSESSMENT CRITERION RANGE 
    These can be based on logical or mathematical errors.
     

    ASSESSMENT CRITERION 3 
    Accuracy errors are identified and reported in the context of the following range statement. 
    ASSESSMENT CRITERION RANGE 
    Including the loss of accuracy due to low precision computations.
     

    ASSESSMENT CRITERION 4 
    Rasterisation of vector data errors are identified and reported in the context of the GIS project. 

    ASSESSMENT CRITERION 5 
    Processing errors are identified and reported in the context of the following range statement. 
    ASSESSMENT CRITERION RANGE 
  • Giving prefernce to the data source of higher authority.
  • Re-executing processes on original data sets.
     


  • UNIT STANDARD ACCREDITATION AND MODERATION OPTIONS 
  • Anyone assessing a learner against this unit standard must be registered as an assessor with the relevant ETQA.
  • Any institution offering learning that will enable achievement of this unit standard must be accredited as a provider through the relevant ETQA by SAQA.
  • Moderation of assessment will be overseen by the relevant ETQA according to the moderation guidelines and the agreed ETQA procedures. 

  • UNIT STANDARD ESSENTIAL EMBEDDED KNOWLEDGE 
    N/A 

    UNIT STANDARD DEVELOPMENTAL OUTCOME 
    N/A 

    UNIT STANDARD LINKAGES 
    N/A 


    UNIT STANDARD ASSESSOR CRITERIA 
    N/A 

    REREGISTRATION HISTORY 
    As per the SAQA Board decision/s at that time, this unit standard was Reregistered in 2012; 2015. 

    UNIT STANDARD NOTES 
    Notes to Assessors:

    This unit standard is essentially an application unit standard. All of the issues identified should have been handled in prior learning activities, the focus here is on identifying and managing errors. Managing data errors may include fixing them, but always includes reporting errors in metadata records and to data custodians. 

    QUALIFICATIONS UTILISING THIS UNIT STANDARD: 
      ID QUALIFICATION TITLE PRE-2009 NQF LEVEL NQF LEVEL STATUS END DATE PRIMARY OR DELEGATED QA FUNCTIONARY
    Core  63711   Bachelor of Geographical Information Science (GISc)  Level 7  NQF Level 07  Reregistered  2018-06-30   
    Elective  63689   Bachelor of Arts: Geographical Information Science  Level 6  Level TBA: Pre-2009 was L6  Reregistered  2018-06-30   


    PROVIDERS CURRENTLY ACCREDITED TO OFFER THIS UNIT STANDARD: 
    This information shows the current accreditations (i.e. those not past their accreditation end dates), and is the most complete record available to SAQA as of today. Some Primary or Delegated Quality Assurance Functionaries have a lag in their recording systems for provider accreditation, in turn leading to a lag in notifying SAQA of all the providers that they have accredited to offer qualifications and unit standards, as well as any extensions to accreditation end dates. The relevant Primary or Delegated Quality Assurance Functionary should be notified if a record appears to be missing from here.
     
    NONE 



    All qualifications and part qualifications registered on the National Qualifications Framework are public property. Thus the only payment that can be made for them is for service and reproduction. It is illegal to sell this material for profit. If the material is reproduced or quoted, the South African Qualifications Authority (SAQA) should be acknowledged as the source.