Language for us humans is as natural a breathing,

but for a machine it is a huge problem.

Introducing Understanding Language by Machines

Spinoza Prize project by Prof. dr. Piek Vossen.

The Spinoza Prize was awarded in 2013 by NWO (Netherlands Organisation for Scientific Research) and gave Piek Vossen the opportunity to … form a research group around …

Abstract Framework

The Reference Machine is an abstract framework: a conceptual machine that can map natural language to the extra-linguistic world as we perceive it and represent it in our brain.The Reference Machine as an abstract framework studies different aspects of understanding and modeling this through novel computer programs. It brings together three key concepts: identity, reference and perspective, and studies these three concepts in relation to each other. In total 6 PhDs and 3 PostDocs have researched various aspects of the above problems.

Physical Robot

The Reference Machine is not only a conceptual model that illustrates the complexity of the relations between identity, reference and perspective, but is also a real machine in the physical world that reasons and communicates from its own perspective. This is embodied by our robot project. Pepper robot Leolani shares the world with us but perceives it differently. In order to communicate adequately about the world, a robot needs to relate its perception of the world to the way we perceive it.

Three fundamental concepts overarch the research:


What is identity? If all the things in the world are given and identified, e.g. by a number, it would be easy to identity them. You could simply refer to the record number, the 12th thing in the world.


So what is reference? Reference is the relation between an expression and a thing in the world. There are also infinite ways to refer to the infinite things in the world.


What is Perspective? A simple spatial definition of ‘Perspective’ is the point of view from the source to the world. Depending on where you stand, you will see certain things and not others. So what of the world is revealed to us depends on our perspective.




A Reference Machine

The idea of The Reference Machine serves as an abstract framework to study identify, reference and perspective.

It encloses several projects addressing: language and AI, human-robot communication, sensory data and language.

Pepper robot Leolani is a first personification of The Reference Machine. Leolani is an engineering project applying our scientific research.

How to communicate with such a thing?

There is No Such Thing as Simple Text

Texts, images and sounds, we are not even talking of odours and touch, all kinds of sensory data, computers still have poor interpretations of these signals.

Myriad of Technologies Involved

A lot of technologies are involved, like: speech recognition, object recognition, face recognition, language technology and semantic web technology.

Do Androids Dream?

When interacting with machines people bring expectations, fears, hopes and fantasies. When communicating with humanoid robots we often project emotions, intensions, consciousness, a will, motivation and other human experiences and drives.

There is no such thing as a perfect machine...

There is no airplane!

Recognize me? I'm Lenka!

Leolani, listen to me!

... and there's infinite ambiguity for machines...

Ambiguity demo

Sound Similarity demo

Visualing Uncertainty demo


Identifying the world



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