Here are some quotes I found:
Hard as in solid and soft as in liquid: [George Siemens as cited by Remote Access]
Knowledge possesses different states.....along a continuum. Hard knowledge occurs in fields and eras where change is slow. Through a process of expert validation and acceptance of the public, knowledge acquires solid states.
Differentiated by people's ability to articulate/codify: [Paul M. Hildreth and Chris Kimble The duality of knowledge]
The part of what people know that can be articulated we will simply term 'hard knowledge' and the part of what people know that cannot be articulated we will term 'soft knowledge'.
hard knowledge as being 'codifiable' ... soft knowledge as that which is less quantifiable and cannot be so easily captured and stored.
[Emile Durkheim Many Faces Exploring Knowledge]
Hard as in physical and soft as in human-nature:
[Ngiam Tong Dow Singapore must not alienate its brightest]
America's invasion of Iraq was an example of hard power. Winning the hearts and minds of the people is soft power.
In classical Chinese thought, the equivalent distinction would be 'wen' and 'wu', the pen and the sword, or the scholar and the warrior. The Chinese ideal is a combination of the scholar and the warrior in the same individual.
The difference between hard and soft can also be applied to knowledge, distinguishing between 'hard knowledge' and 'soft knowledge'. Rocket science, which requires heavy investment in jet-propulsion technology, is hard knowledge. Researching demand for luxury cars in developing countries requires soft knowledge.
[complied by Carter McNamara Sales Staffing and Training]
"Hard" Knowledge and Skills
Advertising and Marketing Laws
Advertising and Promotion
Ethics: Practical Toolkit for Business
Positioning: Deciding and Conveying Your Unique Selling Position
Public and Media Relations
"Soft" Knowledge and Skills ("People Skills")
Handling Difficult People
Presenting / Speaking
Dimensions of Core Knowledge Types:
Hard Knowledge ("what Button does what")
Fuzzy Knowledge ("what sequence of actions in Blender makes sense in order to achieve a certain result")
Soft Knowledge ("what looks cool and what looks bad and how do I seperate the two", "how do I aproach a certain task in Blender")
Dimensions of Fringe Knowledge Types:
Hard Knowledge ("how do I set up a Blender render cluster", "how do I build models for the Torque Game Engine")
Fuzzy Knowledge ("what other tools make sense in a Blender 3D pipeline", "how is the human body built", "what result demands which tool")
Soft Knowledge ("what narrative styles are there", "what visual style supports/demands which type of poetic essence")